Iliffe, J. K., author
MacDonald, 1968
Buku Teks
Bertrand, Alvin L
Appleton-Century Crofts, 1973
Buku Teks
Catlin, Avery, author
Prentice-Hall, 1992
Buku Teks
Gottfried, Byron S., author
Erlangga, 1988
Buku Teks
Allen, B.L., author
W.H. Preman, 1970
Buku Teks