by Prof. Dr. S. Nasution, M.A.
$7.00

by Ir. Moehar Daniel, M.S & Ir. Darmawati, M.Sc & Ir. Nieldalina, M.Si
$7.00

by Drs. Surajiyo
$7.00

by Aa Dani Saliswijaya, S.H
$11.00

by Denny J. A
$9.00

by Bachtiar Ibrahim
$12.00