by Prof. Dr. Sondang P. Siagian, M.P.A $11.00
by Denny J. A $6.00
by Dr. Ir. Supli Effendi $7.00
by - $12.00
by AM Fatwa $11.00
by Prof. Drs. H. A. W. Widjaja $9.00
by - $6.00