edited by Stephen K. Bailey
United States Information Agency, 1973
Buku Teks SO
Sperber, Hans
McGraw-Hill, 1962
Buku Teks SO
Dreier, John C.
Harper & Row , 1962
Buku Teks SO
Coupland, R.
McMillan, 1935
Buku Teks
Jose, James R.
The Scarecrow Press, 1970
Buku Teks SO