Butzer, Karl W., author
Cambridge University Press, 1982
Buku Teks
Harold
Princeton University Press, 1965
Buku Teks
Last, John M., 1926-, author
McGraw-Hill, 1997
Buku Teks
Burnet, Macfarlane
St. Martin's Press, 19770
Buku Teks
Tivy, Joy, author
Oliver and Boyd, 1981
Buku Teks