Sloan, A
Hutchinson , 1924
Buku Teks
Halliday, Fred, author
Cambridge University Press, 2005
Buku Teks
edited by Sydney Nettleton Fisher
Cornell University Press , 1955
Buku Teks
Lenczowski, George, author
Cornell University Press, 1956
Buku Teks
Bill, James A., author
Little, Brown, 1979
Buku Teks