Gopal, Sarvepalli
Oxford University Press , 1984
Buku Teks
Gopal, Sarvepalli
Oxford University Press, 1979
Buku Teks
Craven, Paul R.
Dickenson Publishing, 1968
Buku Teks
Gopalan, K. Gopal
IRWIN, 1996
Buku Teks
Nagrath, I.J.
Wiley Eastern Limited, 1978
Buku Teks