How to Cite Sources in APA Format Step by Step in 2026

Knowing how to cite sources in APA format step by step is a non-negotiable skill for any student writing a thesis, dissertation, or research paper. APA style — published by the American Psychological Association — is the dominant citation format in the social sciences, education, nursing, and many STEM disciplines. It governs not only how you list references, but how you acknowledge sources within the text itself, making every decision about attribution visible and verifiable.

As of 2026, APA 7th edition (published in 2020) remains the current standard. It introduced several important changes from the 6th edition that students frequently miss: a higher author threshold before using “et al.”, the removal of location requirements for publishers, updated DOI formatting, and more inclusive language guidelines. If you learned APA from older guides, this article will clarify what has changed and what stays the same.

This guide walks through in-text citations and reference list entries for every source type you will commonly encounter in thesis writing, with exact format examples you can adapt directly to your own work.

Why APA Format and When to Use It

APA was designed for scientific disciplines where the currency of knowledge matters — citing the year prominently signals how recent a source is, which is critical in fast-moving fields. It is the required style for most journals in psychology, sociology, education, business, communication, criminology, and health sciences. Many universities also require APA for interdisciplinary programmes.

If you are unsure which citation style your department requires, check your thesis guidelines or ask your supervisor. Do not assume — switching citation styles midway through a thesis is a significant task. For a broader comparison of citation formats, see our guide on what citation style to use for your thesis.

Step 1: Master In-Text Citations

APA uses the author-date system. Every time you refer to an idea, finding, or argument from another source, you insert a brief parenthetical citation in the text that points the reader to the full reference in your reference list.

The basic format is: (Author’s Last Name, Year)

Examples:

• One author: (Smith, 2022)
• Two authors: (Smith & Jones, 2021)
• Three or more authors: (Smith et al., 2020)
• No author: (Title of Source, Year) — use a shortened title in italics for a book, in quotation marks for an article
• Organisation as author: (World Health Organization, 2023)

You can also write citations in narrative form, where the author’s name appears as part of the sentence rather than in parentheses:

• Narrative: Smith (2022) argued that…”
• Narrative with two authors: Smith and Jones (2021) found…”
• Narrative with three or more: Smith et al. (2020) demonstrated…”

When the same idea is supported by multiple sources, list them alphabetically by author within a single parenthetical, separated by semicolons: (Brown, 2019; Chen, 2021; Smith, 2022).

Step 2: Cite Direct Quotations Correctly

Whenever you reproduce an author’s exact words, you must include a page number (or paragraph number for sources without pages) in addition to the author and year.

Short quotations (fewer than 40 words) are embedded within the text and enclosed in double quotation marks:

Smith (2022) described this as “a fundamental shift in how organisations understand expertise” (p. 47).

Long quotations (40 words or more) are formatted as block quotations: indented 0.5 inches from the left margin, no quotation marks, with the citation appearing after the final punctuation mark:

Smith (2022) outlined the implications at length:

    [Indented text of 40+ words goes here.] (p. 112)

Use direct quotations sparingly in academic writing. Paraphrasing demonstrates deeper engagement with the source material and is generally preferred by examiners and journal editors alike.

Step 3: Cite Paraphrases and Summaries

When you restate an author’s idea in your own words, you still need an in-text citation. APA 7th edition encourages (but does not require) including a page number for paraphrases — doing so is considered good practice, especially when citing specific arguments from long texts.

Example: Research on distributed teams suggests that informal communication is harder to maintain remotely, with significant implications for knowledge retention (Smith, 2022, p. 47).

One of the most common errors in thesis writing is paraphrasing too closely — changing a few words while preserving the structure and most of the phrasing of the original. This constitutes plagiarism even if you have included a citation. True paraphrase requires re-expressing the idea entirely in your own sentence structure and vocabulary.

Step 4: Set Up Your Reference List

Your reference list appears at the end of the document on a new page. Format it as follows:

• Centred heading: References (bold)
• Entries listed alphabetically by the first author’s last name
• Hanging indent format (first line flush left, subsequent lines indented 0.5 inches)
• Double-spaced throughout
• No blank lines between entries

The general formula for a reference entry is: Author, A. A., & Author, B. B. (Year). Title of work. Source. https://doi.org/xxxxx

Step 5: Cite Journal Articles

Journal articles are the most common source type in academic theses. The format is:

Author, A. A., & Author, B. B. (Year). Title of article. Journal Name, Volume(Issue), page–page. https://doi.org/xxxxx

Key rules:

• Italicise the journal name and the volume number
• Do not italicise the issue number (it appears in parentheses immediately after the volume)
• Only capitalise the first word of the article title and any proper nouns
• Capitalise every major word in the journal name
• Always include the DOI when available — format as a URL (https://doi.org/…)

Example:

Smith, J. A., & Brown, C. (2022). Remote work and knowledge transfer in technology firms. Journal of Organizational Behaviour, 43(2), 115–134. https://doi.org/10.1002/job.12345

Step 6: Cite Books and Book Chapters

Entire book:

Author, A. A. (Year). Title of book (edition, if not first). Publisher. https://doi.org/xxxxx (if applicable)

Creswell, J. W., & Creswell, J. D. (2018). Research design: Qualitative, quantitative, and mixed methods approaches (5th ed.). SAGE.

Note: APA 7th edition no longer requires the publisher’s city and state for book references.

Chapter in an edited book:

Author, A. A. (Year). Title of chapter. In E. E. Editor (Ed.), Title of book (pp. xxx–xxx). Publisher.

Brown, T. (2020). Distributed cognition in remote teams. In M. J. Davies (Ed.), Handbook of organisational psychology (pp. 234–251). Academic Press.

Step 7: Cite Websites and Online Sources

For websites, the format is:

Author, A. A. (Year, Month Day). Title of page. Site Name. URL

World Health Organization. (2024, January 15). Global health statistics 2024. https://www.who.int/data/global-health-estimates

Key rules for web sources:

• Include a retrieval date only if the content is likely to change (e.g., a wiki page or a live database)
• Omit “Retrieved from” before the URL — APA 7th edition removed this requirement
• If there is no individual author, use the organisation name as the author
• If there is no date, write (n.d.) in place of the year

Step 8: Cite Other Common Source Types

Key Changes in APA 7th Edition

If you learned APA from 6th edition materials — or from a supervisor who learned it even earlier — you need to know what changed:

• Et al. threshold lowered: In 6th edition, you used “et al.” for sources with six or more authors. In 7th edition, use “et al.” for sources with three or more authors, both in-text and in the reference list (after listing all authors up to 20 in the reference).
• Running head no longer required for student papers: Running heads are only required for manuscripts submitted for publication.
• Publisher location removed: Book references no longer require the city and country of the publisher.
• DOI formatted as URL: DOIs are now formatted as full URLs (https://doi.org/…) rather than the old “doi:” prefix format.
• Up to 20 authors listed: In 6th edition, you listed six authors then used ellipsis. In 7th edition, list all authors up to 20, then use an ellipsis before the final author.

For a complete visual overview of APA 7th edition formatting — including page margins, font, and heading styles — see our detailed walkthrough on how to format your thesis in APA style.

Most Common APA Errors in Thesis Writing

• Capitalising article titles incorrectly. Only the first word of the title, the first word after a colon, and proper nouns are capitalised. “The Effect of Remote Work on Knowledge Sharing” is wrong; “The effect of remote work on knowledge sharing” is correct.
• Missing DOIs. If a journal article has a DOI, include it. No exceptions.
• Mismatch between in-text citations and the reference list. Every in-text citation must have a corresponding entry in the reference list, and vice versa.
• Using the wrong edition rules. Working from 6th edition guidelines when your institution requires 7th edition will produce systematic errors throughout.
• Incorrect italicisation. In a journal reference, the journal name and volume number are italicised; the issue number is not.
• Citing secondary sources. If you have not read the original source, find and read it. Citing “Smith, as cited in Jones” is acceptable when the original is truly unavailable, but it is a last resort.

Managing citations manually across a 20,000-word thesis is a high-error-rate process. Tesify’s Auto Bibliography feature eliminates formatting errors by generating APA-compliant references automatically as you write. For the thesis introduction and literature review in particular — where citation density is highest — this can save several hours of manual checking. Visit tesify.app to see how it works.

For related content, see our guide on APA citation format: every rule with examples for every source type.

Frequently Asked Questions