by Susmayati, B.A., dkk $11.00
by Prof. Dr. Sondang P. Siagian, M.P.A $9.00
by Ir. Sarjoni Basri $12.00
by Richard G. Lipsey & Peter O. Steiner $16.00
by Dra. Ninik Widiyanti $12.00
by Kelly S. $5.00