Olexiy Y. Chebykin, Gregory Z. Bedny, Waldemar Karwowski
CRC Press, 2008
Buku Teks
Sidanius, Jim, author
Cambridge Uiversity Press, 1999
Buku Teks
edited by R. Murray Thomas
Pergamon Press, 1990
Buku Referensi
Reed, Stephen K., author
Thomson Wadsworth, 2004
Buku Teks
Reed, Stephen K., author
Australia, 1999
Buku Teks