Harper, Michael C
Little, Brown and Company, 1996
Buku Teks
by Clark Kerr ... [et al.]
Oxford University Press, 1964
Buku Teks
Sloane, Arthur A., author
Prentice-Hall,
Buku Teks
Johnson, Carol, author
Allen and Unwin, 1989
Buku Teks
Morgan, Chester A., author
The Dorsey Press, 1962
Buku Teks