edited by Ian Wilson
Angus and Robertson, 1973
Buku Teks
Simmonds, J.D., author
Columbia University Press, 1970
Buku Teks
Kaushik, Devendra
Sterling Publishers, , 1975
Buku Teks
Hinton, Harold C., author
Houghton Miffiln, 1966
Buku Teks
Barnett, A. Doak (Arthur Doak), author
Overseas Development Council, 1979
Buku Teks