1. Lecturer in the Faculty of Economics, Universitas Sarjanawiyata Tamansiswa, Yogyakarta, Indonesia
2. Lecture in Department of Business Administration, Faculty of Social and Political Sciences, Diponegoro University, Semarang, Indonesia
3. Master in Economic Science, Faculty of Economics, Universitas Sarjanawiyata Tamansiswa, Yogyakarta, Indonesia
4. Lecturer in the Faculty of Economics, Muhammadyah University of Yogyakarta, Indonesia