1. Zeplin J. H. Tarigan:
Master of Management Department, Petra Christian University, 60236 Surabaya, Indonesia
2. Sautma R. Basana:
Management Department, Petra Christian University, 60236 Surabaya, Indonesia
3. H. Siagian:
Master of Management Department, Petra Christian University, 60236 Surabaya, Indonesia
4. W. Suprapto:
Management Department, Petra Christian University, 60236 Surabaya, Indonesia