National Academy Press, 1985
Buku Teks
Chandler Publishing Company, 1961
Buku Teks
Langdon, Robert M., author
Littlefield Adams, 1961
Buku Teks
McCamy, James L., author
Alfred A. Knopf, 1952
Buku Teks
Pratt, Julius W., author
Prentice-Hall, 1965
Buku Teks