by Prof. DR. Taliziduhu Ndraha $13.00
by Dr. Sofyan Syafri Harahap, M.S,Ac $7.00
by Dr. Marwan Effendi, SH $12.00
by Prof. Dr. S. Nasution, M.A. $7.00
by - $9.00
by Endik Koeswoyo $6.00
by $7.00