Palmer, Norman D.
Houghton Mifflin, 1971
Buku Teks
Lok Sabha Secretariiat, 2002.
Buku Teks
Frankel, Francine R.
Princenton University Press, 1978
Buku Teks
Pylee, M.V.
Asia Publishing House, 1960
Buku Teks
Calman, Leslie J.
Westview Press, 1985
Buku Teks