Long, Larry E., author
Prentice-Hall, 1994
Buku Teks
Rosenberg, Jerry M., author
John Wiley & Sons, 1993
Buku Referensi
Watson, Hugh J., author
Businesss Publications , 1980
Buku Teks
Hellwig, Jessica
Columbia University Press, 1969
Buku Teks
Carver, Keith R., author
Wiley, 1983
Buku Teks