Steele, James
Phaidon Press, 1997
Buku Teks
McCune, George M.
Harvard University Press, 1950
Buku Teks
Buckley, Roger
Cambridge University Press, 1990
Buku Teks
International Society for Educational Information, 1989
Buku Teks
Woolf, Emile
Prentice-Hall, 1986
Buku Teks