Lytel, Allan, author
Howard W. Sams, 1964
Buku Teks
Crawford, F. Robert, author
Prentice-Hall, 1973
Buku Teks
Gregory, Robert Henry, author
Chatto and Windus, 1963
Buku Teks
Gleim, George A., author
McGraw-Hill, 1956
Buku Teks
Couger, J. Daniel, author
John Wiley & Sons, 1984
Buku Teks