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Harvard referencing uses in-text citations, in an author-date format.
Sometimes you might be referencing a source that has more than one author. Or, you might reference several different sources by the same author published in the same year.
This page gives you guidelines and examples for using Harvard in these scenarios.
If you are citing more than one source by the same author which are also published in the same year, you will need to differentiate between the sources in your in-text citations.
You can do this by adding a lower-case letter to the publication date in your in-text citation, and again in your reference list so that the dates and letters match. The first reference should appear as (Author, Yeara), the second as (Author, Yearb) and so on.
The rest of the reference should follow the usual style for the type of source you are citing.
In-text citations:
(Kubler-Ross, 1993a)
(Kubler-Ross, 1993b)
Reference list:
Kubler-Ross, E. (1993a). AIDS: The ultimate challenge. New York, NY: Collier Books.
Kubler-Ross, E. (1993b). Questions and answers on death and dying. New York, NY. Collier Books.
If you are citing a source with two or three authors, the surname of all of the authors should be listed in your in-text citation. You should keep the names in the same order as they are in the source.
The surname and initial(s) of all the authors should appear in the full reference for the source.
The rest of the reference should follow the usual style for the type of source you are citing.
In-text citation:
(Reiss and White, 2013, p.6)
Reference list:
Reiss M. J. and White, J. (2013). An aims-based curriculum: the significance of human flourishing for schools. London: IOE Press.
If you are citing a source with four, five, six or seven authors, the surname of only the first person attributed as one of the source's authors should be included in your in-text citation, followed by the words 'et al'.
The surname and initial(s) of all the authors should appear in the full reference for the source.
The rest of the reference should follow the usual style for the type of source you are citing.
In-text citation:
(Rogers et al., 2018)
Reference list:
Rogers, L., Hallam, S., Creech, A. and Preti, C. (2018). ‘Learning about what constitutes effective training from a pilot programme to improve music education in primary schools’, Music Education Research, 10(4), pp.485-497.
If you are citing a source with eight or more authors, the surname of only the first person attributed as one of the source's authors should be included in your in-text citation, followed by the words 'et al'.
The surname and initial(s) of the first eight attributed authors should appear in the full reference for the source, followed by the words 'et al'. If there are more than eight authors, do not include the word 'and' between the seventh and eight author.
The rest of the reference should follow the usual style for the type of source you are citing.
In-text citation:
(Clark et al., 2020)
Reference list:
Clark, K., Cletheroe, D., Gerard, T., Haller, I., Jozwik, K., Shi, K., Thomsen, B., Williams, H., et al. (2020). ‘Synchronous subnanosecond clock and data recovery for optically switched data centres using clock phase caching’, Nature Electronics, 3, pp.426-433.