by Prof. Dr. Sondang P. Siagian, M.P.A $9.00
by Prof. Dr. H. Nursid Sumaatmadja $7.00
by Julius R. Latumaerissa, S.E., M.M $7.00
by - $12.00
by Suhardjo $6.00
by Yunasril Ali $7.00