by Kasiyanto Kasemin $7.00
by Rosalie Mengsio $11.00
by Ir. Budi Rafitas $7.00
by Arifin Pasaribu $5.57
by Richard G. Lipsey & Peter O. Steiner $16.00
by Drs. Amin Widjaja Tunggal, Ak., M.B.A $6.00