by Prof. Ir. Zoer'ani Djamal Irwan, M.Sc $7.00
by Eileen Rachman (Kata Pengantar) $7.00
by Dr. Ahmad Hasan $13.00
by - $9.00
by Prof. Dr. S. Nasution, M.A. $7.00
by Dwi Suwiknyo $3.75