The Council of Science Editors (CSE) citation style offers three distinct systems for citing sources in scientific papers: Name-Year (parenthetical citations), Citation-Sequence (numbered by appearance), and Citation-Name (numbered by author). Understanding which system your instructor or journal requires—and how to format every source type correctly—is the difference between a well-documented paper and one flagged for citation errors.
Here’s what most student guides miss: CSE doesn’t use punctuation between author initials, doesn’t abbreviate single-word journal titles, and handles the “et al.” rule differently than APA. These are the exact details that trip up science students—and the ones this guide clarifies.
What Is CSE Citation Style?
CSE style (officially Scientific Style and Format) is the citation standard for the Council of Science Editors. It’s designed for scientific and technical writing, where brevity and clarity matter. Unlike APA—which uses commas and parentheses in citations—CSE strips punctuation to its minimum.
Where is CSE used?
- Biology and life sciences
- Earth sciences
- Computer science
- Engineering disciplines (especially when journals require it)
- Some medical and health science programs
What about the 8th edition?
The current official manual is the 8th edition (Scientific Style and Format, 2021). The previous 7th edition used the “CBE” name (Council of Biomedical Editors), which still appears in older course syllabi. Both editions follow the same three systems; formatting details differ slightly.
The CSE style’s defining characteristic is flexibility. Instead of forcing every author into one format, it offers three systems—each suited to different writing needs. Your choice depends on your course requirements or target journal.
CSE Name-Year System: The APA-Like Approach
The Name-Year system is the most similar to APA. It uses parenthetical in-text citations that include the author’s surname and year of publication.
In-Text Citations
Name-Year citations always include author name(s) and year, enclosed in parentheses:
One Author: (Smith 2021)
Two Authors: (Haggarty and Gaynor 2008) — Note: use “and”, not “&”
Three or More Authors: (Coyne et al. 2001) — “et al.” is used for 3+ authors in-text
Multiple Sources: (Smith 1999; Hofmann 2024) — separate with semicolons
Same Author, Different Years: (Smith 2019a, 2019b) — lowercase letters for same-year, same-author
Narrative Citation: Smith (2021) argued that... — author name in running text
Key differences from APA:
- No comma after the author’s name before the year
- No “et al.” abbreviation in the reference list (list up to 10 authors)
- No comma separating authors in the end reference (use commas between authors in the reference list)
End Reference Examples (Name-Year System)
Journal Article:
[Author(s)]. [Year]. [Article title]. [Journal title abbreviated];[volume]:[pages].
Smart N, Fang ZY, Marwick TH. 2003. A practical guide to exercise training for heart failure patients. J Card Fail. 9(1):49-58.
Book:
[Author(s)]. [Year]. [Book title]. [Place]: [Publisher].
De Doncker RW, Duco WJP, Veltman A. 2020. Advanced electrical drives: analysis, modeling, control. Springer.
Chapter in a Book:
[Author(s)]. [Year]. [Chapter title]. In: [Editor(s)], editors. [Book title]. [Place]: [Publisher]; [p #–#].
Website:
[Author(s) or Corporate author]. [Year]. [Title of page]. [URL] [accessed Day Month Year].
Formatting Rules for Name-Year
- Author Names: Last name, initials (no periods after initials, no “&” between authors)
- Journal Titles: Abbreviate when longer than one word. Do not abbreviate single-word titles.
- Italicization: Book titles are italicized. Article titles are not.
- No Hanging Indent: CSE does not use hanging indents in the reference list (simple numbered list).
- Et Al Rule: In the end reference, list up to 10 authors. Only use “et al.” in-text when citing 3+ authors.
CSE Citation-Sequence System: Numbered by Appearance
The Citation-Sequence system uses superscript numbers in the text to point to numbered entries in the reference list. References are numbered in the order they first appear in the document.
In-Text Citations
This system uses a superscript numeral raised above the line of text:
This finding was confirmed by multiple studies1.
Recent research1,2 has demonstrated...
Several factors influenced the outcome2-4.
Multiple citations: Use commas for separate sources (,1,2) and hyphens for consecutive ranges (2-4).
Note vs. Narrative: Unlike Name-Year, Citation-Sequence rarely uses narrative citations. The superscript format is the standard approach.
How the Reference List Works
The reference list is ordered numerically by appearance (first cited = #1, second cited = #2, etc.):
1. Smart N, Fang ZY, Marwick TH. 2003. A practical guide to exercise training for heart failure patients. J Card Fail. 9(1):49-58.
2. De Doncker RW, Duco WJP, Veltman A. 2020. Advanced electrical drives: analysis, modeling, control. Springer.
Each entry follows the same Name-Year format for the reference itself, but the list is ordered by citation sequence, not alphabetically.
When to Use Citation-Sequence
Citation-Sequence is preferred when:
- A paper cites many sources (the superscript numbers stay concise)
- The discipline expects traditional scientific formatting (biology, geology)
- The target journal mandates it (many science journals use this system)
CSE Citation-Name System: Numbered by Author
The Citation-Name system also uses superscript numbers, but the numbers correspond to an alphabetically ordered reference list.
In-Text Citations
Like Citation-Sequence, Citation-Name uses superscript numbers. However, the numbers always refer to the same alphabetical reference regardless of when the source is cited:
This finding was confirmed by multiple studies1,2.
The theory was originally proposed by Smith1 and later expanded by Jones2.
How the Reference List Works
The reference list is alphabetized by first author, then numbered:
1. De Doncker RW, Duco WJP, Veltman A. 2020. Advanced electrical drives: analysis, modeling, control. Springer.
2. Smart N, Fang ZY, Marwick TH. 2003. A practical guide to exercise training for heart failure patients. J Card Fail. 9(1):49-58.
The numbering is fixed—author “De Doncker” is always #1, “Smart” is always #2—regardless of where in the text each is cited.
When to Use Citation-Name
Citation-Name is preferred when:
- A reference list needs to be easily searchable by author (handy in review articles)
- The discipline values alphabetical convenience over chronological order
- A book or thesis cites many sources from varied fields
CSE Reference List: Complete Examples by Source Type
Here are the essential reference list formats, with formatting notes after each.
Journal Article
Format:
[Author(s)]. [Year]. [Article title]. [Journal abbreviated];[volume]:[pages].
Example:
Smart N, Fang ZY, Marwick TH. 2003. A practical guide to exercise training for heart failure patients. J Card Fail. 9(1):49-58.
Notes:
- Use commas to separate author last names and initials
- No periods after initials
- Journal title is abbreviated (standard NLM abbreviation when possible)
- Volume number is not italicized
- Page range uses an en dash (not hyphen)
Book
Format:
[Author(s)]. [Year]. [Book title]. [Place]: [Publisher].
Example:
De Doncker RW, Duco WJP, Veltman A. 2020. Advanced electrical drives: analysis, modeling, control. Springer.
Notes:
- Book title is italicized
- No “ed.” notation for edition unless multiple editions are listed
- Publisher name is not abbreviated
Chapter in an Edited Book
Format:
[Author(s)]. [Year]. [Chapter title]. In: [Editor(s)], editors. [Book title]. [Place]: [Publisher]; [p #–#].
Example:
Langdon A. 2020. Fit for a dog? Food sharing and the medieval human/animal divide. In: Smith J, editor. Medieval studies. London: Routledge; p 41-55.
Notes:
- “In:” precedes the editor(s)
- “editors.” follows the editor names (singular: “editor.”)
- Page range is preceded by “p” or “pp” (singular/plural based on page count)
Website / Online Source
Format:
[Author(s) or Corporate author]. [Year]. [Title]. [URL] [accessed Day Month Year].
Example:
National Institutes of Health. 2021. Guide to scientific formatting. https://www.ncbi.nlm.nih.gov/styleguide/ [accessed 10 May 2026].
Notes:
- Include access date for websites (unless the content is static and unlikely to change)
- URL format: use
https:// or http:// (prefer https)
- No DOI required for websites (though some journal articles may include one)
Conference Proceedings
Format:
[Author(s)]. [Year]. [Paper title]. In: [Conference name], [Conference location]; [Date].
Example:
Ross LD. 2019. The Bengal tiger: population trends and conservation strategies. In: International Wildlife Congress, Sacramento (CA); 2019 Jun.
Notes:
- Conference location is in parentheses after the name
- Date format: YYYY MMM (year, month)
CSE vs APA: Key Formatting Differences
Students often switch between CSE and APA depending on their discipline. Here’s what changes—and what stays the same.
| Feature |
CSE Name-Year |
APA 7th Edition |
| Author separation |
Commas (Smith JA, Doe JB) |
Ampersand (Smith, J. A., & Doe, J. B.) |
| Initials |
No periods (Smith JA) |
Periods (Smith, J. A.) |
| Year placement |
After authors in parentheses: (Smith 2021) |
After authors in parentheses: (Smith, 2021) |
| Et al. |
Used at 3+ authors in-text; up to 10 in reference |
Used at 3+ authors (2021) or 7+ (2019) |
| Journal abbreviation |
Standard NLM abbreviations |
Only abbreviate journal names up to 6 letters |
| Hanging indent |
Not used |
Required (0.5 inch) |
| Reference ordering |
Alphabetical (N-Y) or by appearance (C-S/C-N) |
Alphabetical |
| Italicization |
Book titles only; article titles not italicized |
Article titles not italicized; journal titles italicized |
The biggest trap: Students trained in APA tend to add commas after author names in CSE citations. CSE (Name-Year) formats as (Smith 2021)—no comma.
Choosing the Right System: Decision Guide
Which CSE system should you use? The answer depends on your audience.
Use Name-Year when:
- Your professor or instructor requests it
- You’re writing for a journal that uses parenthetical citations
- You prefer the APA-like approach (easier for social science students)
Use Citation-Sequence when:
- Your target journal explicitly requires it (many biology journals)
- You’re writing a paper with heavy citation density
- The discipline prefers chronological ordering of references
Use Citation-Name when:
- You’re writing a review or thesis with many sources
- Alphabetical sorting of references is preferred
- Your department or journal mandates it
Rule of thumb: When in doubt, ask your instructor or check the journal’s author guidelines. CSE is flexible, but it’s not free choice—your instructor or journal determines which system is required.
Common Mistakes Science Students Make with CSE
Even experienced writers make these errors. Avoid them:
Mistake 1: Adding periods after initials
Smith J. A. → Correct: Smith JA
CSE removes periods after initials. This is one of the most common formatting errors.
Mistake 2: Using “&” instead of “and”
Smith J. A. & Doe, J. B. → Correct: Smith JA, Doe JB
CSE uses commas (not ampersands) to separate authors in the reference list.
Mistake 3: Mixing systems within one paper
Every citation in a single paper must use the same system. Switching between Name-Year and Citation-Sequence mid-document is a formatting error.
Mistake 4: Abbreviating single-word journal titles
Journal of Biology → Correct: Journal of Biology (keep full)
Only abbreviate journals with more than one word. Single-word titles remain unabbreviated.
Mistake 5: Using hanging indent
CSE does not use hanging indents. The reference list is a plain, numbered list with left-aligned entries.
Mistake 6: Forgetting “et al.” in-text
When citing a paper with 3+ authors, use “et al.” in the parenthetical citation. Always include the year: (Coyne et al. 2001).
Mistake 7: Confusing C-S with C-N ordering
Citation-Sequence numbers by appearance. Citation-Name numbers alphabetically. Don’t mix the two approaches.
Step-by-Step: How to Format a CSE Citation
Let’s walk through formatting a journal article in all three CSE systems:
Source Information:
- Authors: Haggarty, P. and Gaynor, L. A.
- Year: 2008
- Title: Exercise interventions for heart failure patients
- Journal: Journal of Cardiac Failure (abbreviated: J Card Fail)
- Volume: 9, Issue: 1, Pages: 49-58
Step 1: Format the reference entry
Haggarty P, GaynorLA. 2008. Exercise interventions for heart failure patients. J Card Fail. 9(1):49-58.
Step 2: Create the in-text citation (Name-Year)
(Haggarty and Gaynor 2008) or Haggarty and Gaynor (2008) argued that...
Step 3: Create the in-text citation (Citation-Sequence)
...exercise interventions improve outcomes.1
Step 4: Create the in-text citation (Citation-Name)
...exercise interventions improve outcomes.1
(Note: the superscript number is the same regardless of system; what changes is how the reference list is ordered and numbered.)
Tools for Managing CSE Citations
While you can format CSE manually, citation managers can save significant time—especially when a paper requires many references.
Zotero supports CSE natively with both Name-Year and Citation-Sequence options. Add it through the “Add Style” menu by searching “Council of Science Editors.”
Mendeley includes CSE Name-Year and Citation-Sequence styles in its built-in style library.
RefWorks offers CSE with all three formatting options.
Note: Never rely solely on citation-generating tools without verifying the output against the official 8th edition. Some automated tools still output outdated 7th edition formatting. For complete details on managing references across disciplines, see our guide to citation generators compared.
Final Checklist Before Submission
Before you submit your paper, verify these items:
- [ ] Chosen one system and used it consistently throughout the entire paper
- [ ] All in-text citations have a matching reference entry
- [ ] Author initials have no periods (e.g., Smith JA, not Smith J. A.)
- [ ] Authors separated by commas, not ampersands
- [ ] Journal titles abbreviated correctly (single-word titles kept full)
- [ ] Book titles italicized; article titles not italicized
- [ ] No hanging indent in the reference list
- [ ] “et al.” used correctly (3+ authors in-text, up to 10 listed in reference)
- [ ] Reference list ordered correctly (alphabetical N-Y, sequential C-S, or alphabetical C-N)
- [ ] Access dates included for websites
- [ ] Page ranges use en dashes, not hyphens
Summary
CSE (Council of Science Editors) citation style is the standard for scientific writing because it offers three distinct systems—Name-Year, Citation-Sequence, and Citation-Name—each suited to different disciplines and audiences. The style’s defining features include abbreviated journal titles, comma-separated author names without ampersands, and periods after initials.
Key takeaways:
- Pick one system and stick with it. Don’t mix Name-Year, Citation-Sequence, or Citation-Name within the same paper.
- The 8th edition is the current standard. The older “CBE” label (Council of Biomedical Editors) still appears in some course materials.
- Author formatting is distinct: no periods after initials, commas instead of ampersands.
- Your instructor or target journal determines which system to use—ask before guessing.
- Always verify automated citations against the official manual. Automated tools can misformat.
Related Guides
For related topics, see our comprehensive resources:
Frequently Asked Questions
Q: How many authors should I list in a CSE reference?
A: List up to 10 authors in the end reference. Only use “et al.” in-text when there are 3 or more authors.
Q: Can I mix CSE systems in one paper?
A: No. Each paper must use exactly one system throughout. Switching mid-document is considered a formatting error.
Q: What’s the difference between CSE 7th and 8th edition?
A: The 8th edition (Scientific Style and Format, 2021) is the current manual. The primary difference is updated terminology and a few minor formatting changes. The three systems remain the same.
Q: Do I need a DOI in CSE citations?
A: DOIs are not mandatory for CSE, but they’re increasingly acceptable for online journal articles. If a DOI is available, you can include it. Otherwise, a URL or access date is sufficient for web sources.
Q: Should I use “and” or “&” between authors?
A: Always use “and” in narrative text and commas (not “and” or “&”) in the reference list. Never use “&” in CSE formatting.
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