by - $11.00
by Penyunting: Arief Priyadi $6.00
by - $12.00
by - $7.00
by Mangasa Sidabutar $7.00
by Eddy Tano, Dipl. Chem. Eng. $7.00
by Ir. Rudy Gunawan $6.00
by dr. Samsuridjal Djauzi $7.00
by Drs. H. Ahmad Yani $13.00
by dr. J.F. Shipley $5.00