Davidson, Jon P., author
Prentice Hall, 1997
Buku Teks
Tarbuck, Edward J., author
Maxwell Macmillan, 1993
Buku Teks
Longwell, Chester R., author
John Wiley & Sons, 1964
Buku Teks
Skinner, Brian J., author
John Wiley & Sons, 1987
Buku Teks
McGeary, David, author
McGraw-Hill, 2004
Buku Referensi