DeMars, Brent, author
Thompson, 2004
Buku Teks
Swerdlik, Mark E.
Mayfield Publishing Company, 1999
Buku Teks
Jackson, Richard H., author
John Wiley & Sons, 1982
Buku Teks
Lucas, Henry C., author
McGraw-Hill, 1981
Buku Teks
Sherwood, Lauralee, author
West Pub. , 1989
Buku Teks