Ziegler, David M., author
Little, Brown, 1981
Buku Teks
Lyon, Peter, author
Oxford University Press, 1969
Buku Teks
Lyon, Peter, author
Oxford University Press , 1969
Buku Teks
May, Mark A.
Yale University Press, 1943
Buku Teks
Hutchinson, 1950
Buku Teks