1. Postgraduate School, Universitas Khairun Ternate, Ternate, North Maluku, Indonesia
2. Postgraduate Department, Institut Agama Islam Tazkia, Bogor, Indonesia
3. Badan Pusat Statistik, Central Jakarta, Indonesia
4. Fakultas Ekonomi dan Bisnis, Universitas Dr Soetomo, Surabaya, Indonesia