Tiersky, Ronald, author
Wadsworth, 1993
Buku Teks
edited by Andrew Blasko, Diana Januauskiene
Council for Research in Values and Philosophy, 2008
Buku Teks
E & FN Spon, 1999
Buku Teks
Fisher, H.A.L.
Edward Arnold & Co., 1946
Buku Teks
Fisher, H.A.L.
Eyre and Spottiswoode , 1935
Buku Teks