Combs, James E., author
Macmillan, 1984
Buku Teks
Islam, Syed Serajul, author
Thomson, 2005
Buku Teks
Tansey, Stephen D., author
Routledge, 1996
Buku Teks
Eulau, Heinz, author
Bobbs-Merrill, 1963
Buku Teks
Dyke, Vernon van, author
Nelson, 1992
Buku Teks