1. Universitas Muhammadiyah Yogyakarta - Economics, Bantul, Yogyakarta, Indonesia,
2. Heriot-Watt University - Economics, Edinburgh, United Kingdom of Great Britain and Northern Ireland; Universitas Muhammadiyah Yogyakarta – Economics, Bantul, Yogyakarta, Indonesia,
3. Heriot-Watt University - Economics, Edinburgh, United Kingdom of Great Britain and Northern Ireland; National Institute of Economic and Social Research, London, United Kingdom of Great Britain and Northern Ireland,