Robert T. Golembiewski, Glenn H. Varney, editor
F.E. Peacock Publisher, 2000
Buku Teks
Litterer, Joseph August, 1926-, author
John Wiley & Sons, 1973
Buku Teks
Pfifner, John M., author
Prentice-Hall, 1960
Buku Teks
Ritchie, J.B., author
West Publshing Company, 1980
Buku Teks
Kast, Fremont Ellsworth, author
McGraw-Hill, 1976
Buku Teks