Kothari, C.R.
Vikas Publishing House, 1978
Buku Teks
Reinke, William A.
The John Hopkins University Press , 1972
Buku Teks
Biegel, John E.
Prentice-Hall, 1978
Buku Teks
edited by Daniel F. Merriam
Pergamon Press, 1976
Buku Teks
Frank, Ronald E.
Richard D. Irwin, 1962
Buku Teks