Turner, Bryan S.
Sage, 1983
Buku Teks SO
edited by John A. Kromkowski, Robert R. Magliola and George F. McLean
Council for Research in Values and Philosophie, 2004
Buku Teks SO
Wasby, Stephen L.
Charles Scribner`s Sons, 1973
Buku Teks
Nancy LoPatin-Lummis, editor
Wiley-Blackwell, 2008
Buku Teks SO
edited by Donald Eugene Smith
Free Press, 1971
Buku Teks SO