Blair, John M., author
Johnson Reprint Corporation, 1972
Buku Teks
Bellinger, William Kenneth, author
Routledge, 2007
Buku Teks
Luksetich, William A., author
Little, Brown, 1982
Buku Teks
Bromley, Daniel W., 1940-, author
Basil Blackwell, 1989
Buku Teks
Oxford University Press , 1993
Buku Teks