Q. Am I allowed to use secondary references? (quote someone else's quote)

Generally, secondary referencing should be avoided where possible, as without reading the original work you cannot fully understand the full intention of that quote.

However, if - for exceptional reasons - you do wish to include the quotation without seeing the original you must make it clear to your reader which author you have read, whilst giving details of the original. To do this you would generally add a note (for instance, 'Cited in:') to your citation or footnote indicating that the author is being cited from a secondary source.

More information on secondary citations is available in the library referencing guides and departmental style guides.