by Moenaf H. Regar $7.00
by John Adair $9.00
by Drs. Abu Ahmadi $9.00
by Drs. H. Malayu S.P. Hasibuan $7.00
by Prof. Dr. Sondang P. Siagian, M.P.A $11.00
by Drs. H. Moh. Pabundu Tika, M.M $7.00