Sober, Elliott: Core questions in philosophy: A text with readings. Third edition (first edition 1991). Upper Saddle River, New Jersey: Prentice Hall, 2001. ISBN 0-13-083537-4. (englanniksi)
Kenny, Anthony: A brief history of western philosophy. Oxford: Blackwell, 1998 (third edition 2005). ISBN 0-631-18791-X. (englanniksi)