Friedman, Myles T., author
Praeger, 1991
Buku Teks
Bonner, Hubert
American Book Company, 1953
Buku Teks
Bracken, Peg
Fawcett Publications, 1969
Buku Teks
Crow, Lester D.
Littlefield, Adams & Co., 1961
Buku Teks
Davis, Robert H.
McGraw-Hill, 1974
Buku Teks