by Prof. Ir. Zoer'ani Djamal Irwan, M.Sc $7.00
by Syahrin Harahap $9.00
by Prof. Komaruddin $7.00
by K. Usman $6.00
by Drs. Slameto $7.00
by Bustamin & M. Isa H.A. Salam $6.00