edited by Shanti Sadiq Ali
Hind Pocket Books, 1994
Buku Teks
edited by Gerald Moore and Ulli Beier
Penguin Books, 1963
Buku Teks
edited Brian M. du Toit
Westview Press, 1978
Buku Teks
Washington, D.C :Worl bank, 1996.,
Buku Teks
Marcus, Edward, author
Bookman Associates, 1960
Buku Teks