1. Dr., Accounting Department, Faculty of Economics and Business, Universitas Sumatera Utara, Medan
2. Professor, Department of Accounting, Faculty of Economics and Business, Universitas Sumatera Utara, Medan, North Sumatera
3. Master of Accountancy, Faculty of Economics and Business, Universitas Sumatera Utara, Medan, North Sumatera
4. Professor, Accounting Research Institute, Universiti Teknologi MARA