Davidson, Jon P.
Prentice Hall, 1997
Buku Teks
McGeary, David
McGraw-Hill, 2004
Buku Referensi
Skinner, Brian J.
John Wiley & Sons, 1987
Buku Teks
Press, Frank
W H Freeman , 1974
Buku Teks
Hamblin, W. Kenneth [William Kenneth], 1928-
Burgen Publishing, 1985
Buku Teks SO