Barnard, Alan
Cambridge University Press, 2011
Buku Teks SO
edited by Marc J. Swartz, Victor W. Turner and Arthur Tuden
Aldine Pub. Co., 1966
Buku Teks SO
Pawson, Ivan G.
John Wiley & Sons, 1977
Buku Teks SO
Baradat, Leon P.
[Publisher not identified], [Date of publication not identified]
Buku Teks SO
Brace, C. Loring
Macmillan, 1969
Buku Teks