Strategic Direction Publishers, [date of publication not identified]
Buku Referensi
Strategic Direction Publishers, [date of publication not identified]
Buku Referensi
Dahlgaard, Jens J., author
Chapman & Hall, 1998
Buku Teks
Prentice-Hall, 2003
Buku Teks
Fakultas Ekonomi dan Bisnis Universitas Indonesia, 1997
UI - Skripsi (Membership)