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

by Redaksi Rineka Cipta
$18.00

by Aziz Alimul
$7.00

by Drs. H. Burhanuddin Salam, M.M
$11.00

by IBNU MUHAMMAD SALIM
$6.00

by Yasa Boga
$6.00