Crockett, James Underwood
Time-Life Books, 1972
Buku Referensi
Brennan, Lynne
Platkus, 1991
Buku Teks
Becker, Norman
McGraw-Hill, 2011
Buku Teks
Augusto Rinaldi
Crescent Books, 1985
Buku Referensi
Budworth, Geoffrey
Chancellor Press , 1997
Buku Referensi