Harvard NMBU - Guideance

The following guidelines are based on the Harvard Referencing System, also called the author/date system.

A bibliographical reference must contain enough information to enable a reader to identify and find the source.

1. Citing written sources
   1.1 Inserting references in a text
   1.2 Multiple authors
   1.3 Two or more publications cited in one citation
   1.4 Secondary sources
   1.5 Documents without year of publication
2. Citing non-written sources
3. How to make a good reference list
   3.1 Books
   3.2 Edited publications
   3.3 Publications issued by organisations/institutions
   3.4 Masters theses
   3.5 Articles /chapters in edited books
   3.6 Journal articles
   3.7 Online documents

1. Citing written sources

1.1 Inserting references in a text

When writing scientific you often need to use texts written by others. This is called citing, and it must be clear for the reader of your text where you cite from. Therefore, a citation always is followed by a reference, providing the author’s last name and the year of publication (and sometimes the page you are citing from).

In a second step, the reader must be able to obtain the complete bibliographical information about your source. All written sources that have been cited are therefore organized in a reference list at the end of your text, which is sorted alphabetically by the author’s last name.

References can be incorporated into a text in many ways, and your writing will improve if you use various strategies. For example, a reference to something you read on page 3 in a book by Smith, published in 2018, can be written in one of the following ways: 

• In her study on mad cow disease, Smith (2018, p. 3) states that …
• Smith (2018, p. 3) claims that mad cow disease is caused by …
• As shown by Smith (2018, p. 3) …
• In the book ”Mad Cow Disease” from 2018, Smith (p. 3) states that …

Sometimes you have to refer to a large number of pages. In such cases, it is sufficient to refer to a chapter, section, etc.:

• Smith (2018, chap. 4)

From a reader’s point of view, including the page number(s) is ideal. However, text references very often only refer to author and year.

1.2 Multiple authors

A publication can be written by many authors. If there is more than one author, there are certain rules to follow for the in-text citation. In any case, all authors must be listed in the reference list.

If a text is published by two authors, both are mentioned in the in-text citation.

• (Smith & Avery, 2017)

If a text is published by three or more authors, only the first author is mentioned. Use the abbreviation et al. (from Latin et alii, meaning "and others") to indicate that there are more authors.

• (Smith et al., 2016)

Some authors publish numerous articles within a single year. When referring to two (or more) of such articles, you must add a, b, etc. to distinguish between them:

• Smith (2018a, p. 113) and (2018b, p. 217) clearly indicates that …

If two authors with the same last name have published an article in the same year, use their first-name initial to distinguish:

• Both A. Smith (2018, p. 3) and B. Smith (2018, p. 46) agree that …

1.3 Two or more publications cited in one citation

Separate authors of different publications by a semicolon if you refer to two or more publications at the same place in your text:

• (Avery 2000; Brown 1991; Smith 2016)

1.4 Secondary sources

Using a secondary source means referring to the source you want to use via another (secondary) source (ie if an author refers to a publication you have not read). This should be avoided, but at times it may be impossible to obtain the primary source. However, it must be clearly stated in your reference that you have not seen the book/article you are referring to.

• In 1987, Smith (cited in Jones, 2017, p. 3) discovered that the entire …

1.5 Documents without year of publication

Written sources without a year of publication are cited by using the abbreviation s.a. (Latin: sine anno – without year):

• Smith (s.a., p. 5)

2. Citing non-written sources

The citing rules for non-written sources, f. ex. films and videos, follow those for written sources – stating author and publishing year. Remember to include URL and access date in the reference list when referring to online sources.

However, there is a different rule for all personal communication (f. ex. email, interview, …). Personal communication is referred to in the text, but usually not included in the reference list.

• According to B. Smith, professor in biology at NMBU (e-mail 26th of May 2018), ...

3. How to make a good reference list

The aim of the reference list is to enable the reader to easily identify and find the sources you used.

There are two main rules for what to include in the reference list.
     1. All literature referred to in the text must be included in the reference list.
     2. All references in the reference list must be found as citations in the text.

The reference list follows alphabetical order sorted by author’s last name, and further on by year (if various publications by the same author). Use title for sorting publications without author.

3.1 Books

A reference to a book with a personal author shall include the following information:
     Author’s last name, first name (or only first name initial), year of publication, book title, place of publication, publisher.

• Pillay, T. V. R. (2004). Aquaculture and the environment. 2nd ed. Oxford: Fishing News Books.

The year of publication is distinguished by parentheses. The book title is written in italics. For books that have been issued in several editions, the reference must state which edition was used.

Example of several references to publications by the same author (the oldest publication is listed first):

• Pillay, T.V.R. (1992). Aquaculture and the environment. Oxford: Fishing News Books.
• Pillay, T.V.R. (2004). Aquaculture and the environment. 2nd ed. Oxford: Fishing News Books.

Publications with several authors: List up authors with last name first. Use an ampersand (&) between the two last authors.

• Schafer, J., Beaudet, P. & Haslam, P. A. (2012). Introduction to international development: approaches, actors, and issues. Don Mills, Ont: Oxford University Press.

3.2 Edited publications

For edited publications, the references are quoted as follows:

• Wilkinson, R. E. (ed.). (2000). Plant-environment interactions. 2nd ed. New York: Marcel Dekker.

3.3 Publications issued by organisations/institutions

When an organization or an institution acts as ”author” and publisher of a book or document, it is common practice to list the organization’s name as the ”author”.

• United Nations. Department of Economic and Social Affairs. (2001). World public sector report: globalization and the state. New York: United Nations.

• UNESCO. (2003). Gender and education for all: the leap to equality. Paris: Unesco.

If such a report was prepared by one or several authors, but is issued as part of an institute’s publication series, you can choose if you want to refer to the author or the institution.

3.4 Master theses

An example of a reference to a Master’s thesis submitted at NMBU:

• Rasaily, R. G. (2006). Contribution of community forest on agriculture farming in Mid Hills of Nepal. M.Sc. thesis. Ås, Norwegian University of Life Sciences.

3.5 Articles/chapters in edited books

When citing an article/chapter published in an edited book, you refer to the article’s/chapter’s author and provide the page number:

• Sanders, D. W. (1992). Soil conservation: strategies and policies. In: Tato, K. & Hurni, H. (eds.) Soil conservation for survival, p. 17-28. Ankey, Iowa: Soil and Water Conservation Society.

3.6 Journal articles

A complete reference to an article from a journal/periodical should include:
     Author’s last name, first name (or only first name initial), year of publication, title of article, name of journal (in italics), volume, pages (from:to), doi.

• Strevens, C. M. J. & Bonsall, M. B. (2011). The impact of alternative harvesting strategies in a resource-consumer metapopulation. Journal of Applied Ecology, 48 (1): 102-111. doi: 10.1111/j.1365-2664.2010.01907.x.

Doi is the abbreviation for Digital object identifier. A doi consists of a unique string of numbers, letters and symbols which permanently identifies a document online. If a journal article you use has registered a doi, make sure to provide it in the reference (not all journal articles have registered a doi).

The ISSN Portal is a useful electronic tool for finding the complete titles and standard abbreviations of journals.

3.7 Online documents

In addition to the usual bibliographical information, references to electronic documents must include the URL address and access date (date on which you viewed the document). Exception: For journal articles with doi, you only provide doi (see journal articles).

• Auestad, G. E. (2019). This cheese can be made from trees. Available at: https://www.nmbu.no/en/news/node/37628 (accessed: 02.07.2019).