Filley, Alan C., author
Scott, Foresman, 1969
Buku Teks
Hampton, David R., author
McGraw-Hill, 1986
Buku Teks
Gilmer, B. von Haller (Beverly von Haller), 1909-1994, author
McGraw-Hill, 1977
Buku Teks
Barney, Jay B.
Houghton Miffiln, 1992
Buku Teks
Cabell, Randolph W.
John Wiley & Sons, 1961
Buku Teks