Burnet, Macfarlane, author
William Heinemann, 1968
Buku Teks
Darling, James, author
Hill of Content Publishing, 1978
Buku Teks
Washington, Booker T., author
Oxford University Press, 1900
Buku Teks
Ellis, Mary, author
John Murray, 1982
Buku Teks
Benamou, Michel
Mass., Xerox College Pub, 1971
Buku Teks