Williams, J. D.
Little, Brown and Co., 1980
Buku Teks
Seeley, Harry W.
W H Freeman, 1972
Buku Teks
Giles, J. P.
Rigby, 1962
Buku Teks
McGivering, Ian C.
Liverpool University Press, 1960
Buku Teks
Batten, J.D.
D.B. Taraporevala Sons & Co., 1963
Buku Teks