- Our Program Divisions
- Our Three Academies
- Government Affairs
- Statement on Diversity and Inclusion
- Our Study Process
- Conflict of Interest Policies and Procedures
- Project Comments and Information
- Read Our Expert Reports and Published Proceedings
- Explore PNAS, the Official Scientific Journal of NAS
- Access Transportation Research Board Publications
- Coronavirus Disease 2019 (COVID-19)
- Diversity, Equity, and Inclusion
- Economic Recovery
- Fellowships and Grants
- Publications by Division
- Division of Behavioral and Social Sciences and Education
- Division on Earth and Life Studies
- Division on Engineering and Physical Sciences
- Gulf Research Program
- Health and Medicine Division
- Policy and Global Affairs Division
- Transportation Research Board
- National Academy of Sciences
- National Academy of Engineering
- National Academy of Medicine
- Publications by Topic
- Agriculture
- Behavioral and Social Sciences
- Biography and Autobiography
- Biology and Life Sciences
- Computers and Information Technology
- Conflict and Security Issues
- Earth Sciences
- Energy and Energy Conservation
- Engineering and Technology
- Environment and Environmental Studies
- Food and Nutrition
- Health and Medicine
- Industry and Labor
- Math, Chemistry, and Physics
- Policy for Science and Technology
- Space and Aeronautics
- Surveys and Statistics
- Transportation and Infrastructure
- Searchable Collections
- New Releases

REFERENCE FINDER
Find relevant information like your own rough draft from among the 11,679 reports available for free at NAP.edu. Copy and paste up to 8 pages of content from some other source: an outside article, a rough draft of your own, etc., then select "Find Relevant Reports".
Find Relevant Reports
Click here to search reports published from the National Academy of Sciences, the Institute of Medicine, the National Academy of Engineering, and the National Research Council.
Build Web Searches
Click here to view key search phrases derived from your content for searching on Google, Yahoo, Bing, and NAP.edu.
The Reference Finder is provided exclusively as a research tool. No information will be retained regarding use of this resource beyond normal server logs. That is, entered text is not retained, and the staff of the National Academies will make no correlations between server logs, IP addresses, and submitted content.
What is the Reference Finder?

Explore millions of high-quality primary sources and images from around the world, including artworks, maps, photographs, and more.
Explore migration issues through a variety of media types
- Part of The Streets are Talking: Public Forms of Creative Expression from Around the World
- Part of The Journal of Economic Perspectives, Vol. 34, No. 1 (Winter 2020)
- Part of Cato Institute (Aug. 3, 2021)
- Part of University of California Press
- Part of Open: Smithsonian National Museum of African American History & Culture
- Part of Indiana Journal of Global Legal Studies, Vol. 19, No. 1 (Winter 2012)
- Part of R Street Institute (Nov. 1, 2020)
- Part of Leuven University Press
- Part of UN Secretary-General Papers: Ban Ki-moon (2007-2016)
- Part of Perspectives on Terrorism, Vol. 12, No. 4 (August 2018)
- Part of Leveraging Lives: Serbia and Illegal Tunisian Migration to Europe, Carnegie Endowment for International Peace (Mar. 1, 2023)
- Part of UCL Press
Harness the power of visual materials—explore more than 3 million images now on JSTOR.
Enhance your scholarly research with underground newspapers, magazines, and journals.
Explore collections in the arts, sciences, and literature from the world’s leading museums, archives, and scholars.
Purdue Online Writing Lab Purdue OWL® College of Liberal Arts
Research: Where to Begin

Welcome to the Purdue OWL
This page is brought to you by the OWL at Purdue University. When printing this page, you must include the entire legal notice.
Copyright ©1995-2018 by The Writing Lab & The OWL at Purdue and Purdue University. All rights reserved. This material may not be published, reproduced, broadcast, rewritten, or redistributed without permission. Use of this site constitutes acceptance of our terms and conditions of fair use.
We live in an age overflowing with sources of information. With so many information sources at our fingertips, knowing where to start, sorting through it all and finding what we want can be overwhelming! This handout provides answers to the following research-related questions: Where do I begin? Where should I look for information? What types of sources are available?
Research isn't something that only scientists and professors do. Any time you use sources to investigate claims or reach new conclusions, you are performing research. Research happens in virtually all fields, so it’s vitally important to know how to conduct research and navigate through source material regardless of your professional or academic role.
Choosing and Narrowing Your Research Topic
Before beginning the process of looking for sources, it’s important to choose a research topic that is specific enough to explore in-depth. If your focus is too broad, it will be difficult to find sources that back up what you’re trying to say.
If your instructor gives you the flexibility to choose your own research topic, you might begin by brainstorming a list of topics that interest you ( click here to visit an OWL page that can help you get started brainstorming or prewriting ). Once you find something that grabs your attention, the next step is to narrow your topic to a manageable scope. Some ways to narrow your focus are by sub-topic, demographic, or time period.
For example, suppose that you want to research cancer treatments. Cancer treatment is a fairly broad topic, so you would be wise to at least consider narrowing your scope. For example, you could focus on a sub-topic of cancer treatment, such as chemotherapy or radiation therapy. However, these are still broad topics, so you might also narrow your topic to a narrower sub-topic or even examine how these topics relate to a specific demographic or time period. In the end, you might decide to research how radiation therapy for women over fifty has changed in the past twenty years. In sum, having a specific idea of what you want to research helps you find a topic that feels more manageable.
Writing Your Research Question
Writing your research topic as a question helps you focus your topic in a clear and concise way. It ensure that your topic is arguable. While not all research papers have to offer an explicit argument, many do.
For the above example, you might phrase your research question like this: "How has radiation therapy changed in the past twenty years for women over fifty?" Of course, phrasing this topic as a question assumes that the research has, in fact, changed. Reading your sources (or, to begin with, at least summaries and abstracts of those sources) will help you formulate a research question that makes sense.
Knowing What Types of Sources You Need
Depending on the type of research you’re doing, you may need to use different types of sources. Research is usually divided into scholarly and popular, and primary and secondary. For more information on specific details about these types of sources, visit our "Where to Begin" page in our "Evaluating Sources" subsection. This subsection contains additional pages that explore various kinds of sources (like, e.g., internet sources) in more detail.
Asking Productive Questions
Before you begin your research, you should ask yourself questions that help narrow your search parameters.
What kind of information are you looking for?
Different types of research will require different sources. It’s important to know what kinds of sources your research demands. Ask whether you need facts or opinions, news reports, research studies, statistics and data, personal reflections, archival research, etc. Restricting yourself to only the most relevant kinds of sources will make the research process seem less daunting.
Where do you need to look for your research?
Your research topic will also dictate where you find your sources. This extends beyond simply whether you use the internet or a print source. For example, if you are searching for information on a current event, a well-regarded newspaper like the New York Times or Wall Street Journal could be a useful source. If you are searching for statistics on some aspect of the U.S. population, then you might want to start with government documents, such as census reports. While much high-level academic research relies mainly on the sorts of academic journal articles and scholarly books that can be found in university libraries, depending the nature of your research project, you may need to look elsewhere.

How much information do you need?
Different research projects require different numbers of sources. For example, if you need to address both sides of a controversial issue, you may need to find more sources than if you were pursuing a non-controversial topic. Be sure to speak with your instructor if you are unclear on how many sources you will be expected to use.
How timely does your research need to be?
Depending on your research topic, the timeliness of your source may or may not matter. For example, if you are looking into recent changes in a specific scientific field, you would want the most up-to-date research. However, if you were researching the War of 1812, you might benefit from finding primary sources written during that time period.
Have a language expert improve your writing
Run a free plagiarism check in 10 minutes, generate accurate citations for free.
- Knowledge Base
- Citing sources
How to Cite Sources | Citation Generator & Quick Guide
Citing your sources is essential in academic writing . Whenever you quote or paraphrase a source (such as a book, article, or webpage), you have to include a citation crediting the original author.
Failing to properly cite your sources counts as plagiarism , since you’re presenting someone else’s ideas as if they were your own.
The most commonly used citation styles are APA and MLA. The free Scribbr Citation Generator is the quickest way to cite sources in these styles. Simply enter the URL, DOI, or title, and we’ll generate an accurate, correctly formatted citation.
Generate accurate citations with Scribbr
Table of contents, when do you need to cite sources, which citation style should you use, in-text citations, reference lists and bibliographies.
Scribbr Citation Generator
Other useful citation tools
Citation examples and full guides, frequently asked questions about citing sources.
Citations are required in all types of academic texts. They are needed for several reasons:
- To avoid plagiarism by indicating when you’re taking information from another source
- To give proper credit to the author of that source
- To allow the reader to consult your sources for themselves
A citation is needed whenever you integrate a source into your writing. This usually means quoting or paraphrasing:
- To quote a source , copy a short piece of text word for word and put it inside quotation marks .
- To paraphrase a source , put the text into your own words. It’s important that the paraphrase is not too close to the original wording. You can use the paraphrasing tool if you don’t want to do this manually.
Citations are needed whether you quote or paraphrase, and whatever type of source you use. As well as citing scholarly sources like books and journal articles, don’t forget to include citations for any other sources you use for ideas, examples, or evidence. That includes websites, YouTube videos , and lectures .
Prevent plagiarism. Run a free check.
Usually, your institution (or the journal you’re submitting to) will require you to follow a specific citation style, so check your guidelines or ask your instructor.
In some cases, you may have to choose a citation style for yourself. Make sure to pick one style and use it consistently:
- APA Style is widely used in the social sciences and beyond.
- MLA style is common in the humanities.
- Chicago notes and bibliography , common in the humanities
- Chicago author-date , used in the (social) sciences
- There are many other citation styles for different disciplines.
If in doubt, check with your instructor or read other papers from your field of study to see what style they follow.
In most styles, your citations consist of:
- Brief in-text citations at the relevant points in the text
- A reference list or bibliography containing full information on all the sources you’ve cited
In-text citations most commonly take the form of parenthetical citations featuring the last name of the source’s author and its year of publication (aka author-date citations).
An alternative to this type of in-text citation is the system used in numerical citation styles , where a number is inserted into the text, corresponding to an entry in a numbered reference list.
There are also note citation styles , where you place your citations in either footnotes or endnotes . Since they’re not embedded in the text itself, these citations can provide more detail and sometimes aren’t accompanied by a full reference list or bibliography.
A reference list (aka “Bibliography” or “Works Cited,” depending on the style) is where you provide full information on each of the sources you’ve cited in the text. It appears at the end of your paper, usually with a hanging indent applied to each entry.
The information included in reference entries is broadly similar, whatever citation style you’re using. For each source, you’ll typically include the:
- Author name
- Publication date
- Container (e.g., the book an essay was published in, the journal an article appeared in)
- Location (e.g., a URL or DOI , or sometimes a physical location)
The exact information included varies depending on the source type and the citation style. The order in which the information appears, and how you format it (e.g., capitalization, use of italics) also varies.
Most commonly, the entries in your reference list are alphabetized by author name. This allows the reader to easily find the relevant entry based on the author name in your in-text citation.

In numerical citation styles, the entries in your reference list are numbered, usually based on the order in which you cite them. The reader finds the right entry based on the number that appears in the text.

Because each style has many small differences regarding things like italicization, capitalization , and punctuation , it can be difficult to get every detail right. Using a citation generator can save you a lot of time and effort.
Scribbr offers citation generators for both APA and MLA style. Both are quick, easy to use, and 100% free, with no ads and no registration required.
Just input a URL or DOI or add the source details manually, and the generator will automatically produce an in-text citation and reference entry in the correct format. You can save your reference list as you go and download it when you’re done, and even add annotations for an annotated bibliography .
Once you’ve prepared your citations, you might still be unsure if they’re correct and if you’ve used them appropriately in your text. This is where Scribbr’s other citation tools and services may come in handy:
Plagiarism Checker
Citation Checker
Citation Editing
Plagiarism means passing off someone else’s words or ideas as your own. It’s a serious offense in academia. Universities use plagiarism checking software to scan your paper and identify any similarities to other texts.
When you’re dealing with a lot of sources, it’s easy to make mistakes that could constitute accidental plagiarism. For example, you might forget to add a citation after a quote, or paraphrase a source in a way that’s too close to the original text.
Using a plagiarism checker yourself before you submit your work can help you spot these mistakes before they get you in trouble. Based on the results, you can add any missing citations and rephrase your text where necessary.
Try out the Scribbr Plagiarism Checker for free, or check out our detailed comparison of the best plagiarism checkers available online.
Scribbr Plagiarism Checker
Scribbr’s Citation Checker is a unique AI-powered tool that automatically detects stylistic errors and inconsistencies in your in-text citations. It also suggests a correction for every mistake.
Currently available for APA Style, this is the fastest and easiest way to make sure you’ve formatted your citations correctly. You can try out the tool for free below.
If you need extra help with your reference list, we also offer a more in-depth Citation Editing Service.
Our experts cross-check your in-text citations and reference entries, make sure you’ve included the correct information for each source, and improve the formatting of your reference page.
If you want to handle your citations yourself, Scribbr’s free Knowledge Base provides clear, accurate guidance on every aspect of citation. You can see citation examples for a variety of common source types below:
And you can check out our comprehensive guides to the most popular citation styles:
At college level, you must properly cite your sources in all essays , research papers , and other academic texts (except exams and in-class exercises).
Add a citation whenever you quote , paraphrase , or summarize information or ideas from a source. You should also give full source details in a bibliography or reference list at the end of your text.
The exact format of your citations depends on which citation style you are instructed to use. The most common styles are APA , MLA , and Chicago .
The abbreviation “ et al. ” (Latin for “and others”) is used to shorten citations of sources with multiple authors.
“Et al.” is used in APA in-text citations of sources with 3+ authors, e.g. (Smith et al., 2019). It is not used in APA reference entries .
Use “et al.” for 3+ authors in MLA in-text citations and Works Cited entries.
Use “et al.” for 4+ authors in a Chicago in-text citation , and for 10+ authors in a Chicago bibliography entry.
The Scribbr Citation Generator is developed using the open-source Citation Style Language (CSL) project and Frank Bennett’s citeproc-js . It’s the same technology used by dozens of other popular citation tools, including Mendeley and Zotero.
You can find all the citation styles and locales used in the Scribbr Citation Generator in our publicly accessible repository on Github .
APA format is widely used by professionals, researchers, and students in the social and behavioral sciences, including fields like education, psychology, and business.
Be sure to check the guidelines of your university or the journal you want to be published in to double-check which style you should be using.
MLA Style is the second most used citation style (after APA ). It is mainly used by students and researchers in humanities fields such as literature, languages, and philosophy.
Is this article helpful?
Other students also liked.
- Citation Styles Guide | Examples for All Major Styles
- APA vs. MLA | The Key Differences in Format & Citation
- The Basics of In-Text Citation | APA & MLA Examples
More interesting articles
- Citation examples for common sources types
- Et Al. | Meaning & Use in APA, MLA & Chicago
- Hanging Indent | Word & Google Docs Instructions
- How to Cite a Book | APA, MLA, & Chicago Examples
- How to Cite a Journal Article | APA, MLA, & Chicago Examples
- How to Cite a Lecture | APA, MLA & Chicago Examples
- How to Cite a Newspaper Article | MLA, APA & Chicago
- How to Cite a Website | MLA, APA & Chicago Examples
- How to Cite a Wikipedia Article | APA, MLA & Chicago
- How to Cite a YouTube Video | MLA, APA & Chicago
- How to Cite an Image | Photographs, Figures, Diagrams
- How to Cite an Interview | APA, MLA & Chicago Style
- Parenthetical Citation | APA, MLA & Chicago Examples
- What Are Endnotes? | Guide with Examples
- What Are Footnotes? | Guide with Word Instructions
- What Does Ibid. Mean? | Definition & Examples
- What is a DOI? | Finding and Using Digital Object Identifiers
- What Is an Annotated Bibliography? | Examples & Format
Scribbr APA Citation Checker
An innovative new tool that checks your APA citations with AI software. Say goodbye to inaccurate citations!


IMAGES
VIDEO
COMMENTS
How to Find Sources | Scholarly Articles, Books, Etc. Research databases. You can search for scholarly sources online using databases and search engines like Google Scholar. Library resources. You can find helpful print sources in your institution’s library. ... Make sure that the sources you... ...
Find Relevant Reports. Click here to search reports published from the National Academy of Sciences, the Institute of Medicine, the National Academy of Engineering, and the National Research Council. The Reference Finder is provided exclusively as a research tool.
Enhance your scholarly research with underground newspapers, magazines, and journals. Explore collections in the arts, sciences, and literature from the world’s leading museums, archives, and scholars. JSTOR is a digital library of academic journals, books, and primary sources.
Reading your sources (or, to begin with, at least summaries and abstracts of those sources) will help you formulate a research question that makes sense. Knowing What Types of Sources You Need Depending on the type of research you’re doing, you may need to use different types of sources.
Simply enter the URL, DOI, or title, and we’ll generate an accurate, correctly formatted citation. Generate accurate citations with Scribbr Table of contents When do you need to cite sources? Which citation style should you use? In-text citations Reference lists and bibliographies Scribbr Citation Generator Other useful citation tools