Kothari, Rajni
Little, Brown, 1970
Buku Teks
edited by Larry W. Bowman and Ian Clark
Westview Press, 1981
Buku Teks
Roberts, Geoffrey
Manchester University Press, 1984
Buku Teks
Singh, Robert
Polity Press, 2002
Buku Teks
Jones, Bill
Manchester University Press, 1991
Buku Teks