Jackson, Susan E., author
South Westh Western College, 2000
Buku Teks
Greenlaw, Paul S., author
Harper & Row, 1986
Buku Teks
The Free Press, 1985
Buku Teks
Fakultas Ekonomi dan Bisnis Universitas Indonesia, 1999
UI - Skripsi (Membership)
Schneider, Susan C., author
Prentice-Hall, 1997
Buku Teks