by Ir. R. Bambang Soelarso
$6.00

by Prof. Dr. Sondang P. Siagian, M.P.A
$11.00

by H. Rahmat Rukmana
$5.00

by Djoehana Setyamidjaja, M.Ed
$7.00

by Ir. Arifin Arief, M. P
$5.00

by Ir. Budi Rafitas
$7.00