by Ir. Heinz Frick $6.00
by I. Marsana Windhu $4.00
by B. U. Hadikusumo $6.00
by Drs. Ig. Wursanto $7.00
by Drs. Agus M. Hardjana, M.Sc., Ed $6.00
by B. U. Hadikusumo $5.00