Paz, Mario
Van Nostrand Reinhold, 1986
Buku Teks
Williams, Alan
Kaplan Education, 2005
Buku Teks
edited by Edwin H. Gaylord, Jr., Charles N. Gaylord, James E. Stallmeyer.
McGraw-Hill, 1997
Buku Teks
Ratay, Robert T.
McGraw-Hill, 2010
Buku Teks
edited by Edwin H. Gaylord, Charles N. Gayrold
McGraw-Hill, 1979
Buku Referensi