8.2 Working with secondary (or indirect) references

At postgraduate level you are typically expected to have read widely and consulted the primary literature. On some occasions, you may find that you want to refer to information or a direct quotation taken from a source that has been cited in an article you have read. This constitutes a secondary (or indirect) reference, in that you have not read the original piece of work, but are citing what the author of the article you have read has said about this other author’s work.

In such cases, you need to make it clear you have not consulted the secondary reference, but are citing this from the context of the primary reference you have read. For example:

‘According to Rüggeberg et al., as cited by Knudson et al. (2010), …’

or

‘As noted in Knudson et al. (2010), Rüggeberg et al. showed that…’

By using phrases such as ‘as cited by’ and ‘as noted in’, you are clearly indicating that you have not read the work by Rüggeberg et al., but are referring to the interpretation of this work by Knudson et al. As the paper by Rüggeberg et al. is a secondary reference, it should not be included in your final reference list. Your final reference list should only contain resources you have read (i.e. your primary references). Given the potential for misinterpretation and/or misrepresentation of another author’s work, you should use secondary references sparingly and avoid them if possible. If you do need to use a secondary reference, make this very clear in your text.