What Are DOIs for Research Papers and How Can I Find Them?

What Are DOIs for Research Papers and How Can I Find Them?

In scholarly writing, accuracy in citations is essential. Not only does proper referencing reflect academic integrity, but it also ensures that readers, examiners and other researchers can locate the exact sources you have used. One of the most important elements of contemporary citation systems is the DOI—the Digital Object Identifier. Although many students and researchers see DOIs frequently, fewer understand exactly what they are, how they work, or how to find them when preparing a reference list. This article offers a comprehensive guide to DOIs: what they are, why they matter, where to find them, and what to do if a source does not have one.

1. Understanding What a DOI Is

A DOI, or Digital Object Identifier, is a unique alphanumeric string assigned to a digital research object—most commonly academic and scientific journal articles. The purpose of a DOI is to provide a permanent, stable and reliable identifier that will always lead to the article, regardless of how or where it is hosted online.

URLs often change when publishers restructure their websites, rename files, or migrate content to new platforms. When a URL becomes obsolete, readers encounter broken links or “page not found” errors. DOIs prevent this problem. Each DOI is permanently registered and will always redirect to the correct paper through an updated link known as a “DOI resolver.”

Most DOIs begin with the number 10. and include a prefix (identifying the publisher) and a suffix (identifying the specific article). For example:

10.1016/j.scitotenv.2023.163417

This seemingly cryptic number is far more dependable than a URL. Whether the article moves from one journal site to another, changes platform providers, or receives a redesigned page layout, the DOI will still lead to the correct document.

2. Why DOIs Are Important in Academic Writing

DOIs serve several essential functions in research communication:

• Permanence – DOIs never change, ensuring long-term access to scholarly work.
• Accuracy – They guarantee that readers can locate the exact version of the article you referenced.
• Standardisation – Many referencing styles (APA, Chicago, MLA, Vancouver) now require DOIs for all sources that have them.
• Verification – Examiners and reviewers often check DOIs to verify citations quickly.
• Digital discoverability – DOIs enhance search visibility through indexing services and library databases.

For postgraduate dissertations, theses and journal submissions, omitting a DOI when one exists can be viewed as incomplete referencing. Including the DOI signals professionalism and strengthens the credibility of your bibliography.

3. Where to Find a DOI in the Article Itself

The first and often easiest place to locate a DOI is in the article’s own PDF or HTML version. Publishers typically place the DOI prominently to ensure its visibility. The DOI may appear:

• on the first page of the article, often near the abstract,
• in a header at the top of the PDF,
• in a footer,
• next to bibliographic metadata such as volume, issue and page numbers.

If the DOI is not visible on the article page, check the article’s metadata section on the journal’s website. Many publishers list the DOI under:

• “Article Information”
• “Citations”
• “Metrics”
• “About This Article”

If the PDF and journal site both fail to show a DOI, this does not necessarily mean that none exists—but it does mean you will need to broaden your search.

4. Using Crossref to Search for DOIs

Crossref (crossref.org) is the central DOI registration agency for academic and scientific publications. It stores metadata on millions of scholarly articles across disciplines. When an article has a DOI, Crossref is usually the most reliable place to find it.

To search for a DOI using Crossref:

1. Go to crossref.org.
2. Select the option Search Metadata.
3. Type the article title exactly as written, ideally inside quotation marks.
4. Add the first author’s surname to increase precision.
5. Review the search results for the correct article.

The DOI will appear at the bottom of each bibliographic record, usually in link form, such as:

https://doi.org/10.xxxx/xxxxxx

If you need only the DOI, copy everything after 10. and omit the “https://doi.org/”.

5. Advanced Searches: Crossref Guest Queries

Crossref also provides more advanced search tools for users who need to look up multiple DOIs or who have incomplete citation information. These tools include:

• Bibliographic Query Form – enter full citation details such as author, title, journal, volume and year.
• Simple Text Query – paste an entire reference list for Crossref to scan automatically.

Using these tools allows you to locate DOIs rapidly and reduces errors in long bibliographies such as thesis reference lists. The Simple Text Query feature requires free registration, but the process is quick and the results are highly accurate.

6. What to Do When Crossref Cannot Find a DOI

If Crossref returns no DOI for a paper, there are several possibilities:

• The article genuinely does not have a DOI.
• The article predates the widespread adoption of DOIs.
• The journal is not registered with Crossref.
• The paper exists only in print or was never formally published online.

In these cases, try the following:

• Search Google Scholar for the article title.
• Browse the journal’s own website directly.
• Consult your institutional library’s databases.
• Check subject-specialist indexing services.

If none of these reveal a DOI, it is acceptable to assume that the article does not have one. In that case, use a standard reference format without a DOI or include a stable URL if required by your documentation style.

7. DOIs and Referencing Styles

Different referencing systems have specific requirements regarding DOIs. For example:

• APA 7th edition: Requires DOIs in active, URL-like format (https://doi.org/...)
• Chicago: Recommends DOIs when available, but permits URLs for online access.
• MLA: Allows DOIs but also accepts URLs.
• Vancouver: Encourages DOI use but allows flexibility.

The safest practice is to consult your university or journal guidelines and follow them strictly. Some academic departments require DOIs for all electronic sources, while others allow either format.

8. Why Older Articles May Not Have DOIs

DOIs are a relatively recent invention in the long history of scholarly publishing. Articles published before the early 2000s often lack DOIs unless retroactively assigned—a process that many journals have begun but not completed. Print-only articles and conference proceedings may also lack DOIs, as may grey literature such as reports, working papers and dissertations.

Understanding this helps prevent unnecessary searching. If you are working with older literature, it is normal to encounter articles without DOIs.

9. Ensuring Accuracy in Your Reference List

Including accurate DOIs strengthens your reference list significantly. To ensure correctness:

• Always copy DOIs directly from reliable sources.
• Avoid typing DOIs manually—errors are easy to make.
• Check for misplaced punctuation or missing characters.
• Use the same formatting style consistently throughout the document.

A clean, consistent reference list reflects a high level of academic professionalism and makes it easy for readers to verify sources.

10. Conclusion: Using DOIs to Strengthen Scholarly Communication

DOIs have become an indispensable part of modern academic publishing. They ensure stability, security and accuracy in referencing, and they help researchers locate sources reliably even as digital platforms evolve. By understanding how DOIs work and knowing how to find them—whether in articles, on journal websites or through Crossref—students and researchers can produce more polished, credible and professional academic writing.

A thesis or dissertation that uses DOIs correctly demonstrates attention to detail, respect for scholarly conventions and commitment to high standards of academic communication.

At Proof-Reading-Service.com, our academic editors can help refine your reference list, verify DOIs, and ensure your citations meet the highest scholarly standards for theses, dissertations and journal submissions.