This guide will help you understand how to properly cite sources in APA format, the essential citation format for biology, natural sciences, and scientific research, ensuring your academic work meets the necessary standards.
3 Oca 2026
By
Joe Pacal, MSc
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TL;DR
CSE style offers three systems: citation-sequence (numbers in order of appearance), citation-name (numbers alphabetically), and name-year (author-date). This guide covers all three with examples for journals, books, and online sources. The 9th edition is current. Note: no periods after author initials or journal abbreviations. Perfect for biology and natural sciences.
What is the CSE Citation Format?
The Council of Science Editors (CSE) style is the go-to citation format for researchers in biology, ecology, environmental science, and other natural sciences. Originally developed in the 1960s as the Council of Biology Editors (CBE) style, it has evolved into a comprehensive system used by scientific journals worldwide. The current standard is the CSE Manual, 9th Edition (2024).
Quick Overview: CSE Citation Format
CSE offers three distinct documentation systems, and you should confirm with your instructor or target journal which one to use:
Citation-Sequence: Sources are numbered in the order they first appear in your text. Your reference list follows the same numerical order.
Citation-Name: Sources are numbered alphabetically by author surname. Numbers remain consistent throughout the text regardless of when sources appear.
Name-Year: Similar to APA, this system uses parenthetical citations with author surnames and publication years. The reference list is arranged alphabetically.
A key feature across all CSE systems: journal titles are abbreviated without periods (e.g., "J Exp Biol" not "J. Exp. Biol."), and author initials appear without periods or spaces.
In-Text Citations in CSE
Citation-Sequence System
Number sources sequentially as they appear:
Recent studies have examined bacterial resistance mechanisms¹. The molecular pathways involved show remarkable complexity²,³. Earlier work established foundational concepts¹.
For multiple consecutive references, use an en dash: ⁵⁻⁷
For non-consecutive references, use commas: ²,⁴,⁸
Citation-Name System
Numbers correspond to alphabetical reference list order:
According to research by Adams⁵ and earlier findings by Chen¹...
Name-Year System
Include author surnames and year in parentheses:
Bacterial resistance has been well documented (Morrison and Chen 2023). For three or more authors, use "et al." (Patel et al. 2024).
Reference List Format
Journal Articles
Citation-Sequence/Citation-Name format:
Name-Year format:
For more than 5 authors, list the first author followed by "et al.":
Books
Single author:
Edited volume:
Websites
Include the accessed date and URL:
Dissertations and Theses
CSE Citation Examples by Source Type
Conference Papers
Government Reports
Preprints
Common CSE Mistakes to Avoid
Forgetting journal abbreviations: CSE requires abbreviated journal titles. Use the ISSN List of Title Word Abbreviations to find correct forms.
Including periods in author initials: Write "Morrison JK" not "Morrison J.K." or "Morrison, J. K."
Using "and" or "&" between authors: Separate all authors with commas, including the last author.
Inconsistent system use: Stick to one citation system throughout your paper—don't mix citation-sequence with name-year.
Missing access dates for online sources: Always include when you accessed internet sources.
CSE Citation Tools
Reference managers like Zotero and Mendeley include CSE style templates. For quick verification, the CSE Citation Quick Guide provides formatted examples directly from the publishers.
When working with scientific literature, tools like Wonders AI can help you discover relevant sources and organize your research while ensuring proper attribution.
References
Council of Science Editors. Scientific Style and Format: The CSE Manual for Authors, Editors, and Publishers. 9th ed. Chicago: University of Chicago Press; 2024.
Duke University Libraries. Council of Science Editors (CSE) Citation Style Guide [Internet]. Durham (NC): Duke University; [cited 2025 Jan 2]. Available from: https://guides.library.duke.edu/cse
Dalhousie University Libraries. CSE 8th Edition Citation Style Guide [Internet]. Halifax (NS): Dalhousie University; [cited 2025 Jan 2]. Available from: https://dal.ca.libguides.com/CitationStyleGuide/CSE
