by Drs. Soemarso, S.R $18.00
by - $12.00
by Prof. Mr. Roeslan Saleh $5.00
by Mary Grisez Kweit $13.00
by I. Al-Abyadi, Terj. Halimuddin, S.H $7.00
by Eddy Tano, Dipl. Chem. Eng. $9.00