Meeker, Mary
HarperBusiness, 1996
Buku Referensi
Agustinus Nalwan, author
Elex Media Komputindo, 2000
Buku Teks
Lani Sidharta, author
Elex Media Komputindo, 1996
Buku Teks
Muhammad Abdullah, author
2011
UI - Laporan Penelitian
Petrus Hari Kuncoro Seno, author
Fakultas Ekonomi dan Bisnis Universitas Indonesia, 1999
UI - Laporan Penelitian