Heckert, J. Brooks (Josiah Brooks), 1893-, author
Ronald Press, 1963
Buku Teks
Heckert, J. Brooks (Josiah Brooks), 1893-, author
Erlangga, 1996
Buku Teks
Bradshaw, Thornton F.
Harvard University,, 1950
Buku Teks
Willson, James D., author
John Wiley & Sons, 1981
Buku Teks
Hassler, Russell H., author
Prentice-Hall, 1958
Buku Teks