Allied Publisher Private Limited, 1965
Buku Teks
Bowman, Larry W., author
Westview Press, 1991
Buku Teks
Ghoshal, U.N.
Orient Longmans, 1957
Buku Teks
edited by Robert Chapman and Keith Sinclair
Pauls Book Arcade for the University of Auckland, 1963
Buku Teks
Moore, R J
Oxford University Press, 1988
Buku Teks