Skip to Main Content
It looks like you're using Internet Explorer 11 or older. This website works best with modern browsers such as the latest versions of Chrome, Firefox, Safari, and Edge. If you continue with this browser, you may see unexpected results.

Agriculture, policy and development: Citing references

A guide to finding information in agriculture, policy and development. 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 Agriculture, policy & Development uses a version of the Harvard style for undergraduate and masters work. This page includes guidance on using this style. 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 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.


Your librarian

Profile Photo
Tim Chapman
I am available to offer support on finding information, referencing, using resources and a whole host of other things via email, Teams or in the Library. If you have a query please email me using the link above and I'll get right back to you.........

General rules for citations and references in the Harvard style

When citing someone’s work in your assignments you should include the author surname and year of publication in brackets in the text. There are two formats - put the whole citation in brackets, or just the year in brackets if you want to include the author names as part of your sentence (see examples below).

The citation must be within the sentence to which it refers, usually either at the beginning or end of the sentence unless a comparison is being made, in which case the authors concerned must be cited as appropriate within the sentence. If you have multiple, consecutive sentences from one source you should include a citation in each sentence - but this is poor academic practice, and you should instead look to use more sources and compare and contrast the information from each one. 

How many authors should I include in the in-text citation?

  • One author - just include their surname and the year
    e.g.:    (Gibson, 2018) or Gibson (2018) argues that...
  • Two authors - cite both surnames with 'and' or & between them 
    e.g.:    (Collins and Gibson, 2019) or According to Collins & Gibson (2019)...
  • Three or more authors - cite the first author plus the abbreviation et al. in italics
    e.g.:    (Gibson et al., 2016) or Gibson et al. (2016) have suggested that...

When referring to edited, multi-authored books, just cite the author(s) of that chapter and only include the editor(s) in the full reference in the bibliography.

Citing multiple sources together

If two or more sources are cited together then they should be cited in date order with the oldest first, and separated with semi-colons
e.g.    (Williams, 1969; Chen, 1996; Jones, 2021)

If they are by the same author you do not need to keep repeating the author's surname in the citation. Include the surname and the oldest year first, then separate the other years by semicolons (;). The sources should be ordered by year of publication, with the oldest first. You must include all of the sources separately in your reference list.

e.g.   (NHS, 2016; 2019; 2021)

Multiple references with the same author and year

If there are two references or more references with the same author and year, then use a lowercase letter after the year to distinguish them.
e.g.    2019a, 2019b, etc. Include the distinguishing letter in your citation and in the references list, to distinguish between them.
e.g.    (Gibson, 2019a)  (Gibson, 2019b).

Do I need to include page numbers in my citation?

The author and year are usually sufficient. However, if you use a direct quote you should include the page number in your in-text citation.
e.g.   (Collins and Gibson, 2016, p.32)

All references cited in the text should be listed in the ‘References list’. They should be listed in alphabetical order by author.

For each reference, full details should be given in the following order. All authors/editors must be included.


Authors/Editors, Year (in brackets). Title of book (in italics), Edition if relevant. Place published: Publisher.

Journal articles

Authors, Year (in brackets). Article title. Journal title (in italics), Volume number (in bold) Part number (in brackets), page numbers.

See the examples below for more guidance on citing specific types of publication.

No author/editor?

If you cannot identify the person responsible for the item you want to cite, such as a method of analysis recommended by an organisation, then you should use the organisation name instead, e.g. AOAC International.  If you still cannot identify an author, use the title (see the guidance on citing webpages below)

This video covers the basics of referencing and how to avoid plagiarism. You will need to login using your University email address and password to view the video.

This video gives specific guidance on using the Harvard for Reading style. You will need to login using your University email address and password to view the video.

Citing the most common types of publication

Citing books

Elements to include in your bibliography entry

  1. Author name(s) in the format 'Surname, Initials'
  2. Year of publication (in brackets)
  3. Book title (in italics or underlined)
  4. Edition (if applicable)
  5. Place of publication followed by a colon e.g. London:
  6. Publisher.

Example: book with a single author/editor

Citation in the text:            “Lewis (1996) stated…..” or “…force measuring equipment (Lewis, 1996).”

Reference in the bibliography:     

Lewis, M.J. (1996). Physical properties of foods and food processing systems. Cambridge: Woodhead Publishing.

Example: book with two authors/editors

Citation in the text:            "Fox and McSweeney (2003) stated..." or "... (Fox and McSweeney, 2003)." 

Reference in the bibliography:

Fox, P.F. & McSweeney, P.L.H. (2003). Advanced dairy chemistry Volume 1: Proteins, 3rd ed. New York: Kluwer Academic/Plenum Publishers. 

Example: book with more than two authors/editors

Citation in the text:            "Lanham-New et al. (2011) state..." or "... (Lanham-New, 2011)

Reference in the bibliography:

Lanham-New, S.A., MacDonald, I.A. & Roche, H.M. (eds.) (2011). Nutrition and metabolism, 2nd ed. Chichester: Wiley-Blackwell.

Citing book chapters

Elements to include in your bibliography entry

  1. Chapter author name(s) in the format 'Surname, Initials'
  2. Year of publication (in brackets)
  3. Chapter title
  4. In:
  5. Book editor name(s) in the format 'Surname, Initials' followed by (ed.) or (eds.)
  6. Book title (in italics or underlined)
  7. Edition (if applicable)
  8. Place of publication followed by a colon e.g. London:
  9. Publisher.

Example: book chapter with two authors

Citation in the text:               “….. (Davis & Wilbey, 1990).”

Reference in the bibliography:    

Davis, J.G. & Wilbey, R.A. (1990). Microbiology of cream and dairy desserts. In: Robinson, R.K. (ed.) Dairy microbiology Volume 2, 2nd ed. London: Elsevier Applied Science.    

Example: book chapter with three or more authors

Citation in the text:        “...  (Martin et al., 2003).”

Reference in the biblography:

Martin, P., Ferranti, P., Leroux, C. & Addeo, F. (2003). Non-bovine caseins: quantitative variability and molecular diversity.  In: Fox, P.F. & McSweeney, P.L.H. (eds.) Advanced dairy chemistry, Volume 1: Proteins, 3rd ed. New York: Kluwer Academic/Plenum Publishers. 

Note that all the authors are included in the bibliography.

Citing journal articles

Elements to include in your bibliography entry

  1. ALL Author name(s) in the format 'Surname, Initials'
  2. Year of publication (in brackets)
  3. Article title
  4. Journal title (in italics or underlined) - give the journal name in full, not abbreviated
  5. Volume number (in bold)*
  6. Issue number if available (in brackets)*
  7. Page numbers of the whole article (not just the ones you have used)*

Even if your article is online, you should follow the citation style given in the examples below - there is no need to give the web address or DOI in your reference.

* Note about online only articles - some articles will not have page numbers, or even volume and issue numbers if they are only available electronically. These may only give a reference number. You should include this instead at the end of your reference. See the last example below.

Example: journal article with a single author

Citation in the text:        ... (Birch, 1994)

Reference in the bibliography:   

Birch, G.G. (1994). The chemical basis of sweetness perception in beverages. Food Chemistry, 51, 359-364.

Example: journal article with two authors

Citation in the text:        ... (Al-Otaibi & Wilbey, 2005)

Reference in the bibliography:    

Al-Otaibi, M.M. & Wilbey, R.A. (2005). Effect of chymosin and salt reduction on the quality of ultrafiltrated white-salted cheese. Journal of Dairy Research, 72(2), 234-242.

Example: journal article with three or more authors

Citation in the text:        ... (Leach et al., 1994)

Reference in the bibliography:

Leach, G.C., Pyle, D.L. & Niranjan, K. (1994). Effective diffusivity of total solids and pectic substances from apple tissue. International Journal of Food Science and Technology, 29(5), 547-558.

You must include ALL authors in the reference in the bibliography.

Example: online only journal article without page numbers

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

Reference in the bibliography:

Han, F., Zhou, D., Liu, X., Cheng, J., Zhang, Q. and Shelton, A.M. (2015). Attitudes in China about crops and foods developed by biotechnology. PLoS ONE, 10(9), e0139114.

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' and doesn't yet have these details, just use 'In press' instead.

Citation in the text:    ... (Benardout et al., 2021)

Reference in the bibliography:

Benardout, M., Le Gresley, A., ElShaer, A. and Wren, S. P. (2021). Fructose malabsorption: causes, diagnosis and treatment. British Journal of Nutrition. In press.

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.

If you are citing an online journal article - follow the guidance on citing journal article, not this! If it has a volume number and page numbers it is probably a journal article.

Elements to include in your bibliography entry

  1. Author name(s) in the format 'Surname, Initials', or organisation name if there isn't a person named on the page.
  2. Year information was created or last edited (in brackets)
  3. Page title (in italics)
  4. URL:
  5. Web address
  6. Date you viewed the page (in square brackets)


The citation in the text should be by author and date, as with other sources, though problems can occur where there is no obvious author (see below).     

Citation in the text:    “…..folate is naturally present in some foods, can be added to others, or taken as a supplement (Office of Dietary Supplements, 2018).”

Reference in the bibliography:    

Office of Dietary Supplements (2018). Dietary supplement fact sheet: folate. URL: [6 August 2018]

Can't identify the author?

If you can identify the organisation responsible for the website, then use their name as the author e.g. World Health Organisation. If this is not possible, then use the page title or an abbreviation thereof.

Citation in the text:    “… demonstrated by the traditional manufacture of Camembert (2014).”

Reference in the bibliography:    

Camembert (2014). La fabrication du Camembert. URL: [9 May 2020]

Can't tell what date is was created or updated?

Look for an updated date at the foot of the page. If you can’t find one, then use the year you accessed the information followed by a question mark e.g. (2021?).

If you are citing a web site then you should retain a printed copy of that site on that day as the site can be changed without notice.

Secondary references (citing a source you have read about in a different source)

A secondary reference is used when you are referring to a source which you have not read yourself, but have read about in another source. Where possible, you should always try to read the original of anything you wish to refer to; otherwise you are relying on the author who cited the reference to have interpreted it correctly and not taken it out of context. Use the reference list at the end of the source you are reading to find details of the reference and search for it using the search boxes below.

Search for books on Enterprise

Just type in the first author's surname and a few words from the title.

Search for journal articles on Summon

Type in the first author's surname and first part of the title.

If you can't get hold of the original source you'll need to do a secondary reference and you should make clear that you are not using the original source. Only include the source you have used in your list of references following the guidance above on citing that type of publication.

In-text citation:

According to Gustaffson et al. (2011, as cited by Ustunol, 2014), the industrial world generates more food waste than developing countries.


Ustunol, Z. (2014). Overview of food proteins. In: Ustunol, Z. (ed.) Applied food protein chemistry. Chichester: Wiley.


EndNote logoWhen 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: