Armstrong, Michael, author
Kogan Page Limited, 1995
Buku Referensi
Goyal, R.C., author
Prenctice Hall of India, 1998
Buku Teks
Yoder, Dale, author
McGraw-Hill, 1958
Buku Teks
Northcott, C.H.
Philoshopical Library , 1956
Buku Teks
Kuotsai Tom Liou
Marcel Dekker, 2001
Buku Teks