Pal, Saroj K.
Tata McGraw-Hill, 1982
Buku Teks
Hildebrand, David K., 1940-, author
Duxbury Press, 1996
Buku Teks
Wallis, W. Allen, author
Free Press, 1956
Buku Teks
Universitas Indonesia, 2007
UI - Skripsi (Membership)
Hamburg, Morris, author
Harcourt Brace Jovanovick, 1985
Buku Teks