Short, John Rennie, author
Routledge, 1994
Buku Teks
Ellsworth, John W
McGraw-Hill, 1976
Buku Teks
Sederberg, Peter C.
Chandler & Sharp Publishers, 1977
Buku Teks
Ethridge, Marcus E., author
Wadsworth, 2010
Buku Teks
Lipson, Leslie, author
Prentice-Hall, 1954
Buku Teks