by Imelda Akmal & Sony Sandjaya $12.00
by Richard Weston $32.00
by Prof. Dr. Sondang P. Siagian, M.P.A $7.00
by Prof. H.M. Arifin, M.Ed $9.00
by Drs. Daryanto $11.00
by John F. Saragih $11.00