The Society, 1989
Buku Teks
Benson, Tedd
CT Taunton Press, 1999
Buku Teks SO
Lair, E.A.
McGraw-Hill Book Company, Inc , 1947
Buku Teks SO
Wachsmann, Konrad, 1901-1980
Birkhal'user, 1995
Buku Teks SO
Wilcox, W. Wayne
John Wiley & Sons, 1991
Buku Referensi