by $17.00
by Ir. Hatta Sunanta, B.Sc., MS $5.00
by Ir. H. Rahmat Rukmana $6.00
by Drs. Agus M. Hardjana, M.Sc., Ed $6.00
by Amatullah Shafiyyah & Haryati Soeripno $6.00
by Ir. Abbas Siregar Djarijah $6.00