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Biological sciences: Citing references

A guide to finding information in biological sciences. Includes links to key resources and sources of help.

Whenever you refer to another person's work in your own essay, dissertation or article you must acknowledge them and give full details of your source. You risk being accused of plagiarism if you fail to do so.

The School of Biological Sciences uses the Harvard referencing style. For examples see below.

For general information on referencing, including an explanation of different citation systems, and guidance on citing specific types of publication, see our Citing references guide.

For help with citing specific types of publication contact your subject librarian, Tim Chapman.

For advice on using references in your work, and how to use them to support your arguments, consult the guidance on the Study Advice website or make an appointment with them.

EndNote

EndNote logo

When you do your dissertation you could consider using EndNote to manage your references. This bibliographic management package can be used to store references, and then insert the citation in your Word document, automatically building the bibliography for you in the correct style.

Find out more on our EndNote webpages:

For information on other options for electronic management of your references see our guide to Managing references:

Books with advice on referencing

As well as our citing references guide there are several books in the Library that can help you with referencing in your written work - here are a few examples;

Citing the most common types of publication - School of Biological Sciences

Citing books

Include the following in your reference:

  1. Author/Editor name(s) in the format 'Surname, Initials'
  2. Year of publication (in round brackets)
  3. Book title (in italics) followed by a full stop (in lower case apart from the first letter of the first word and any proper nouns)
  4. Edition (if 2nd ed or later)
  5. Place of publication followed by a comma e.g. London,
  6. Publisher.

Copy the format and punctuation of these examples.

Example: book with a single author/editor

Citation in the text: (Collard, 2019)

Full reference:     
Collard, S.P. (2019) Human physiology. 2nd ed. Duxford, Woodhead Publishing.

Example: book with two authors/editors

Citation in the text:   (Jones & Gamble, 2019)

Full reference:
Jones, A. and Gamble, M. (2019) Microbiology. Champaign, Human Kinetics.

Example: book with three or more authors/editors

Citation in the text:    (Lawson et al. 2024)

Full reference:
Lawson, S.A., MacDonald, I.A., Roche, H.M., Williams, C. & Mills, P. (eds) (2024) Human metabolism. 2nd ed. Chichester, Wiley-Blackwell.

Note that all authors are included in the full reference.

E-books

Where an e-book looks like a printed book (usually PDFs) and you can find all the publication information (including place published and publisher) - cite it in the same way as a printed book (above). You do not need to include the web address.

Where it is not possible to find the publication information include the web address and date accessed instead, as in the example below:

Citation in the text:  (Techco, 2022)

Full reference:
Techco (2022) The Blood Book. Available from https://techco.book.com/ (accessed April 2024).

EndNote tips

  • Print and e-books
    • Use the Reference Type 'Book'
    • Fields to complete:
      • Author: in the format surname, initials, each author on a separate line
      • Year:
      • Title:
      • Place published:
      • Publisher:
      • Edition: if not the first - just add the number e.g. 2nd, 3rd
  • Edited books
    • Use the Reference Type  'Edited book'
    • Fields to add:
      • Editor: in the format surname, initials, each editor on a separate line
      • Other fields the same as above
  • Online only books 
    • Use the Reference Type 'Electronic Book'
    • Complete the same fields as above. Also add:
      • Date Accessed: the date you looked looked at the book in the format day month year e.g. 17 June 2022
      • URL: the web address

Citing book chapters in edited books

Include the following in your reference:

  1. Chapter author name(s) in the format 'Surname, Initials'
  2. Year of publication (in round brackets)
  3. Chapter title  (in lower case apart from the first letter of the first word and any proper nouns)
  4. in followed by book editor(s) name(s) in the format 'Surname, Initials' followed by (Ed.) or (Eds)
  5. Book title (in italics and in lower case apart from the first letter of the first word and any proper nouns)
  6. Edition (if second edition or later)
  7. Chapter pagination in brackets eg (pp. 239-250)
  8. Place of publication followed by a comma e.g. London,
  9. Publisher's name followed by a comma

Include the page extent of the whole chapter when writing your full citation. Put just the pages you have referred to in the in-text citation.

Copy the format and punctuation of these examples.

Example: book chapter with three authors
Citation in the text:     (North et al. 2018)   
North, K., Tellez-Medina, D.I. & Gutierrez, G.F. (2018) Plasma, in Platt, G. (Ed.), Blood science. 2nd ed. (pp. 211-226). Hoboken, Wiley-Blackwell. 

 

Example: book chapter with four or more authors
Citation in the text:     (Plym et al. 2012)

 

Plym, M.F., Ledward, D.A., Le Blanc, C. & Rogers, N. (2012) Metabolism, in Bates, J.G. & Grasson, A.S. (Eds) Enzyme handbook. 2nd  ed. (pp. 179-204) Weinheim, Wiley-VCH. 

 

Note that all authors are included in the full reference.

Citing chapters in online only books

Where an e-book chapter looks like a printed book chapter (usually PDFs) and you can find all the publication information (including place published and publisher) - cite it in the same way as a printed book (above). You do not need to include the web address.

Where it is not possible to find the publication information include the web address and date accessed instead:

  • Chapter author(s) in the format 'Surname, Initials' 
  • Year of publication (in round brackets)
  • Chapter title - Capitalise only the first letter of the first word and any proper nouns.
  • 'in' followed by book editor(s) name(s) in the format 'Surname, Initials' followed by (Ed.) or (Eds)
  • Book title (in italics). Capitalise only the first letter of the first word and any proper nouns.
  • Edition (if 2nd or later)
  • Available from: https://doi.org... or web address
  • Accessed: date in round brackets (accessed January 2024)

Copy the format and punctuation of this example:

TetraCon (2022) Bacterial infections, in The body book. Available from https://bodybook.tetracon.com/ (accessed November 2024). 

EndNote tips

  • For print book chapters
    • Use the Reference Type  'Book Section'
    • Fields to complete:
      • Author: in the format surname, initials. Each author on a separate line.
      • Year:
      • Title: title of chapter 
      • Editor: (include all the editors in the format surname, initials. Each editor on a separate line)
      • Book title:
      • Place published:
      • Publisher:
      • Pages: page numbers for the chapter e.g. 301-335
      • Edition: if not the first - just add the number e.g. 2nd, 3rd
  • For chapters from online only books
    • Use the Reference Type 'Electronic Book Section'
    • Complete all the details above
    • Add URL: the web address
    • Add Access Date: the date you looked looked at the book in the format day month year e.g. 17 June 2022

Note that the default 'Cite Them Right Harvard' style in EndNote does not handle e-book sections very well. Download and use our amended style which corrects these issues:

Alternatively as a final step before submission, create a plain text version of your document. Go to the EndNote toolbar in Word and select 'Convert citations and bibliography' to 'Plain text' (this will be under 'Tools' on the Mac version of the toolbar). This will create a copy of your document which is divorced from EndNote so that you can make final tweaks to the reference to match the guidance above.

Citing journal articles which have page numbers or article reference numbers

Include the following in your reference:

  1. ALL Author name(s) in the format 'Surname, Initials'
  2. Year of publication (in brackets)
  3. Article title (in lower case apart from the first letter of the first word and any proper nouns)
  4. Journal title (in italics) - give the journal name in full, not abbreviated. Use initial capital letters on all significant words.
  5. Volume number in bold
  6. Issue number (if present, in round brackets) in bold
  7. Page numbers or reference number (Include the page numbers of the whole article when writing your full citation, not just the pages you have referred to)

Copy the format and punctuation of these examples.

Example: journal article with a single author

Citation in the text: (Thomas, 2021)

Full reference:   
Thomas, T.F. (2021) Current microbiology research in the UK: a review, Microbiology Frontiers, 2(4), 407-416.

Example: journal article with two authors and an article reference number instead of page numbers

Citation in the text: (Harbord and Sims, 2020)

Full reference:    

Harbord, M. & Sims, S. (2020) Zebra stripes: a review, Zoology Research International, 131, 108973.

Example: journal article with three or more authors

Citation in the text: (Li et al., 2020)

Full reference:
Li, H., Zhang, T., Li, C., Zheng, S., Li, H. & Yu, J. (2020) Ecology of the Plastisphere, Nature & Technology, 122, 109033.

You must include all authors in the full reference.

Citing online journal articles without page numbers or article reference numbers

Include the following in your reference:

  1. ALL Author name(s) in the format 'Surname, Initials'
  2. Year of publication (in brackets)
  3. Article title - in lower case apart from the first letter of the first word and any proper nouns
  4. Journal title (in italics) - give the journal name in full, not abbreviated. Use initial capital letters on all significant words.
  5. Volume number in bold
  6. Issue number (if present, in round brackets) in bold
  7. Available from  - DOI (preceded by https://doi.org/) or Web link
  8. Accessed eg (accessed October 2024)

Copy the format and punctuation of these examples:

Example: online only journal article without page numbers

Citation in the text: (Mossfegh et al., 2015)

Full reference:

Mossfegh, O., Zhou, D., Liu, X., Cheng, J., Zhang, Q. & Shelton, A.M. (2015) Hedgerow surveys: a methodology reconsidered, PLoS    ONE, 10. Available from https://doi.org/10.149/journal.pone.014374 (accessed February 2024). 
Example: an 'In press' article

Articles are often made available before they receive their official publication details (volume and issue number). If an article is shown as 'In press' or 'early online' and doesn't yet have these details, just use (in press) instead.

Citation in the text:  (Kanton et al., 2024)

Full reference:

Kanton, R., Komolsuradej, N., Buathong, N. & Srikrajang, S. (2024) Association between glycaemic control and malnutrition in older adults with type 2 diabetes mellitus: a cross-sectional study, British Journal of Nutrition (in press). Available from https://doi.org/10.1017/S0007114524000175 (accessed February 2024). 

EndNote tips

You should be able to download details for most articles from databases such as Summon, Web of Science, Scopus and PubMed. If you need to type one in from scratch this is the information to include.

For most articles
  • Use the Reference Type 'Journal Article'
  • Complete these fields:
    • Author: in the format surname, initials - each author on a separate line
    • Year:
    • Title: title of the article - in lower case apart from the first letter of the first word and any proper nouns
    • Journal: name of the journal - give the journal name in full, not abbreviated. Use initial capital letters on all significant words.
    • Volume:
    • Issue: (if present)
    • Pages: page numbers or article reference number
For online only articles without page numbers or an article reference number and 'In press' articles
  • Use the reference Type 'Electronic Article'
  • Fields to complete:
    • Author: in the format surname, initials - each author on a separate line
    • Year:
    • Title: title of the article - in lower case apart from the first letter of the first word and any proper nouns
    • Periodical Title: name of the journal - give the journal name in full, not abbreviated. Use initial capital letters on all significant words.
    • Volume:
    • Issue: (put 'in press' here for articles currently being published)
    • Date Accessed: the date you looked at the article in the format day month year e.g. 7 February 2024
    • URL: add the web address for the article (preferably the DOI web address) in the URL field. If there is already a URL in the box check that it goes to the article, not back to the reference on the database you downloaded it from. 

Citing web pages or web sites

You should avoid citing webpages unless you are clear of their quality and suitability for inclusion in academic work. See the 'Websites' tab within this guide for more information on evaluating webpages.

Only follow this guidance if the item you want to reference is not a book, a book chapter or a journal article. When you search the internet you will find many different types of content. The first step to referencing correctly is to recognise what you are looking at.

  • Could it be a book?
    Is it a PDF? Does it have a title page giving the title and the authors/editors? Does it have a place published and publisher on the following page? If 'Yes' it is probably a book - follow the guidance on citing a book.
  • Could it be a book chapter?
    Does it say 'Chapter' on it? Does it have page numbers? If 'Yes' it could be a book chapter - follow the guidance on citing a book chapter.
  • Could it be journal article?
    Does it have an abstract or summary? Does it mention the name of a journal and have a volume number? If 'Yes' it could be a journal article - follow the guidance on citing a journal article.
Citing reputable websites and webpages

Include the following in your reference:

  1. Author name(s) in the format 'Surname, Initials', or organisation that created the page
  2. Year information was created or last edited (in brackets). You might need to scroll to the bottom of the page to find it. If there is no date put (no date)
  3. Page title (in lower case apart from the first letter of the first word and any proper nouns)
  4. Available from followed by the web address
  5. Accessed date in round brackets (accessed November 2024)

Copy the format and punctuation of these examples.

Example: webpage with a named author

Citation in the text:    (Clark, 2020)

Full reference: 

Clark, G. (2020) Risk factors for infective endocarditis. Availablfrom https://ukhsa.blog.gov.uk/2020/12/21/endocarditis/ (accessed February 2024). 
Examples: webpage with an organisation as the author

Example 1:

Citation in the text:     (National Institutes of Health (NIH), Office of Dietary supplements (ODS), 2022)

Full reference: 

National Institutes of Health (NIH), Office of Dietary Supplements (ODS) (2022) Folate: fact sheet for health professionals. Available from http://ods.od.nih.gov/factsheets/Folate-HealthProfessional/ (accessed January 2024). 

Example 2:

Citation in the text:     (Health Standards Agency, 2023)

Full reference: 

Health Standards Agency (2023) Innovations in health care. Available from https://www.hsa.gov.uk/innovations  (accessed November 2023). 

Example 3:

Citation in the text:     (PubBio, 2024)

Full reference: 

PubBio (2024) Human waste treatment. Available from https://biochem.ncbi.nlm.nih.gov/compound/6124 (accessed January 2024). 

Example 4:

Citation in the text:    (BioMed Commission, 2022)

Full reference:

BioMed Commission (2022) General principle of genetics. Available from https://www.biomed.org/sh-proxy/en/?lnk=1&url=https%253A%252F%252Fworkspace..org%252Fsites%252F%252FS%252FCXC%2B1-1969%252FCXC_001e.pdf (accessed January 2024). 
Example: webpage without a date

If there isn't a date on the website, even at the bottom of the page, use 'no date'. 

Citation in the text:  (Genetic manipulation, no date)

Full reference:

Genetic manipulation (no date) Genes UK. Available from https://www.genes.org.uk/reformulation/uk-manipulation timeline  (accessed December 2023). 

EndNote tips

  • Use the Reference Type 'Web Page'
  • Fields to complete:
    • Author: in the format surname, initials - each author on a separate line
      Organisation as the author? Put a comma after the name to ensure it formats correctly e.g. British Nutrition Foundation,
    • Year: use the updated date for the page, if there isn't a date use 'no date'
    • Title: (in lower case apart from the first letter of the first word and any proper nouns)
    • Access Date: the date you looked at the site in the format day month year e.g. 4 February 2024
      Note there is a fault in the Cite Them Right Harvard style which omits the closing bracket after the date. Just type the closing bracket after the year in EndNote for it to appear e.g. 4 February 2024)
    • URL: web address for the page

You can also download our amended 'Cite Them Right-Harvard' style to correct the issue with the missing closing bracket: