Koch, Christopher J., author
Vintage, 2002
Buku Teks
Brown, T. Louise
New York Routledge 1991,
Buku Teks
Knoebl, Kuno
Frederick A. Praeger , 1967
Buku Teks
Webb, James, author
Bantam Books, 2001
Buku Teks
Thompson, W. Scott (Willard Scott), 1942-, author
University of Queensland Press, 1977
Buku Teks