by Drs. Daryanto
$6.00

by Bilson Simamora
$11.00

by Ir. Heinz Frick & Ch. Koesmartadi
$6.00

by Prof. Dr. Husaini Usman, M.Pd & R. Purnomo Setiady Akbar, S.Pd., M.Pd
$11.00

by Abd. Djafar M. Nur
$9.00

by Rofi'l
$5.00