Kumarappa, J.C.
Bombay Vora & Co 1951
Buku Teks
edited by Warren J. Samuels, Jeff E. Biddle, John B. Davis
Blackwell, 2003
Buku Teks
edited by David Greenaway, Michael Bleaney, and Ian Stewart
Routledge, 1991
Buku Referensi
Macgregor, D.H., author
Oxford University Press, 1949
Buku Teks
Roll, Eric
Prentice-Hall, 1959
Buku Teks