Nelson, A. Tom
California Goodyear Pub., 1981
Buku Teks
Nelson, John D.
John Wiley & Sons, 1992
Buku Teks
Hedgecoe, John
Ebury, 1992
Buku Referensi
ed. by Howard S. Rowland
An Aspen publication , 1984
Buku Referensi
Dunne, Lavon J.
McGraw-Hill , 2001
Buku Teks SO