by Dr. Al. Purwa Hadiwardoyo, MSF.
$3.00

by Darmawijaya, St., Pr.
$8.00

by Markus Zahnd
$7.00

by J. F. Dumanauw
$7.00

by Ir. Hatta Sunanta, B.Sc., MS
$5.00

by Ir. Abbas Siregar Djarijah
$5.00