Question

How to cite another author in a book that they were referenced in.

Answer 1

Cite the original source of the quote.

Find it and check it if you can. Distortions and misquotes are much more common than they should be. Don't beleive anyone, anywhere. Check it for yourself.

Answer 2

Yes philips13 has the right idea. If you want to site YOUR source's source, look up that source directly and cite that.

Alternatively, you can cite your source and mention that he is citing another. Example:

Jones (2011) cites Jacobsen as stating, "(quote here)" (p. 12).

In this instance, you do not have to cite the source that Jones used, but just Jones.