by Jonni M.S, M.Sitorus, Nelly K $7.00
by Brooks $18.00
by Dripa Sjabana $7.00
by Prof. Dr. Sondang P. Siagian, M.P.A $7.00
by Prof. C.J. Ebrahim $6.00
by Drs. H. Kahar Masyhur $11.00