Pople, Maureen
St.Lucia:University of Queenssland, 1986
Buku Teks
Katzenbach, Jon R., author
Ballantine Books, 2002
Buku Teks
Charles W. Eliot, edited
P. F. Collier & Son Corporation, 1959 ; 1969
Buku Referensi
Cha In-pyo, author
Sallim , 2009
Buku Teks
Clancy, Tom
G.P.Putnam's Sons, 1986
Buku Teks