Gennaro, Alfonso R., author
Mack Publishing, 1995
Buku Teks
Burrows, William E., author
W.B. Saunders, 1959
Buku Teks
Lowrie, Pauline, author
Cambridge University Press, 1994
Buku Teks
Flynn, John E., author
McGraw-Hill, 1966
Buku Teks
Parker, Margaret J.
A Bailliere Tindall , 1978
Buku Teks