Moore, John A.
Macmillan Publishing Company, 1985
Buku Teks
Griffith, Ernest S.
London Methuen & Co. 1967,
Buku Teks
"S.Chand ,
Buku Teks
edited by Robert E. DiClerico, Allan S. Hammock
McGraw-Hill, 1992
Buku Teks
Rustow, Dankwart A.
Princeton University Press, 1955
Buku Teks