by Daniel Mohammad
$6.00

by Prof. J. Supranto, M.A., APU
$11.00

by Dr. Ir. M. Imadduddin Abdul Rahim, M.Sc
$7.00

by Nh. Dini
$7.00

by WK
$9.00

by M. Yahya Harahap, S.H.
$6.00