Hamblin, W. Kenneth (William Kenneth), 1928-, author
Burgen Publishing, 1985
Buku Teks
Tarbuck, Edward J., author
Maxwell Macmillan, 1993
Buku Teks
McGeary, David, author
McGraw-Hill, 2004
Buku Referensi
Carlson, Diane H., author
McGraw-Hill , 2008
Buku Teks
Davidson, Jon P., author
Prentice Hall, 1997
Buku Teks