Gurtu, Madhu
Munshiram Manoharlal, 1992
Buku Teks SO
Dignen, Bob, author
York Associates, 1999
Buku Teks
Diamond, 2001
Buku Referensi
Agrawal, Giriraj Sharan, author
Diamond pocket books, 2001
Buku Referensi
Chesterman, Andrew, author
Cambridge University Press, 1991
Buku Teks