Citing sources quoted in another source
It is sometimes necessary to quote or make reference to a work that you have not actually read but only encountered in the work of another. Even though you have not read the quoted source you must acknowledge the original source of the information, as well as the work in which it appears, in a parenthetical note.
The name, date and page reference of the work in which information originated should appear first, followed by 'cited' and then the name etc. of the work in which the information was found. Only the work you have read should appear in the reference list at the end of the work.
Neville (1990 cited Wilson 1998, p.89) devised the standard criteria for food tasting surveys.
Although the results of the Bristol Sausage Survey have been described by one scholar as 'seriously misleading' (Brown 1990, p.65 cited Jones 2004, p.87), they have had a great influence on the marketing strategy of industry leaders.
Citing unwritten sources quoted in another source
When making reference to the spoken words of someone other than the author recorded in a text, cite the name of the person and the name of the author, date and page reference of the work in which the quote or reference appears.
In a recent interview (Jones 2004, p.77), Henry Howard said that the British Sausage industry has suffered from decades of under investment in research and development.
As Henry Howard said in an interview with Jones (2004, p70), 'British sausages are widely regarded as the best in the world'.