by Ir. AG. Kartasapoetra $7.00
by Prof. Dr. Sondang P. Siagian, M.P.A $7.00
by Drs. Hg. Suseno Triyanto Widodo $6.00
by Hiro Tugiman $11.00
by ISEI $18.00
by Ir. Endar Sugiarto $9.00