by Drs. B. Suryosubroto $9.00
by Prof. Dr. Sondang P. Siagian, M.P.A $11.00
by Drs. H. Malayu S.P. Hasibuan $7.00
by Drs. Cholid Narbuko dan Drs. H. Abu Ahmadi $7.00
by Toemin, A. Masoem $5.00
by Daniel J. Mueller $7.00