The Ronald Press Company, 1953
Buku Teks
Saraswati, Sri Chandrasekharendra, author
Bharatiya Vidya Bhavan, 1966
Buku Teks
Herman, A.L., author
Westview Press, 1991
Buku Referensi
O`Malley, L.S.S. (Lewis Sydney Steward), 1874-1941, author
Macmillan, Cambridge, ENg. University Press, 1935
Buku Teks
Ishwaran, Karigoudar, author
Westview Press, 1992
Buku Teks SO