by Drs. Slameto $7.00
by Drs. Djohermansyah Djohan $6.00
by Prof. Ir. Zoer'ani Djamal Irwan, M.Sc $7.00
by Dra. Ahmad Rohani H.M., M.Pd $9.00
by Prof. Dr. S. Nasution, M.A. $7.00
by Julius R. Latumaerissa, S.E., M.M $7.00