by Prof. Dr. S. Nasution, M.A. $7.00
by Soepranto. J. $7.00
by Burhan Bungin $9.00
by Djamaluddin Darwis $7.00
by Sukardja, Ahmad $6.00
by Drs. Abdullah Ali, Drs. Misbandono, dan Ir. Eny Rahma $7.00