by Dr. Budi Tri Akoso $11.00
by Prof. Dr. Kees Bertens, MSC $9.00
by $20.00
by A. W. van den Ban & H. S. Hawkins $12.00
by Ir. Eddy Afrianto & Ir. Evi Liviawaty $6.00
by Ir. Abbas Siregar Djarijah $5.00