Gunther, Gerald, author
Foundation Press, 1970
Buku Teks
Oceana Publications, 1958
Buku Teks
Cooley, Thomas M.
Little, Brown and Company, 1898
Buku Teks
Gunther, Gerald, author
Foundation Press, 1973
Buku Teks
by Paul A. Freund [and others]
Little, Brown, 1966
Buku Teks