Deel, Robert
John Wiley & Son , 1997
Buku Teks
Academic Press, 2014
eBooks
Kaiser, William S., author
McGraw-Hill , 2001
Buku Teks
Masonson, Leslie N., author
AMACOM, 2001.
Buku Teks
Abdurrahman Hakim Soesilo, author
Fakultas Ekonomi dan Bisnis Universitas Indonesia, 2012
UI - Skripsi Open