Hansen, Don R., author
South-Western College Publishing, 1997
Buku Teks
Leonard, William patrick, 1898-
Prentice-Hall, 1962
Buku Teks
Maher, Michael W., 1946-, author
Richard D. Irwin , 1997
Buku Teks
Pizzey, Alan, author
Paul Chapman, 1989
Buku Teks
Rayburn, Letricia Gayle, author
Richard D. Irwin, 1989
Buku Teks