Sompie, Glenn J., author
1987
UI - Skripsi Membership
Erick, author
2005
UI - Skripsi Membership
Silaen, Rein Ronald, author
Universitas Indonesia, 1994
UI - Skripsi Membership
Fakultas Ekonomi dan Bisnis Universitas Indonesia, 1999
UI - Skripsi Membership
Fakultas Ekonomi dan Bisnis Universitas Indonesia, 2001
UI - Skripsi Membership