by Drs. D. Hendropuspito, O. C.
$7.00

by Ir. Abbas Siregar Djarijah & Ir. Harsono Puspowardoyo
$6.00

by Dr. Ir. Muhammad Rasyaf, MS
$7.00

by Rachman Sutanto
$9.00

by Mark B. Woodhouse
$9.00

by A. Ariobimo Nusantara & A. Masri Sareb
$6.00