by Fergal Keane $7.00
by Sudarwan Danim $7.00
by Doni Istyanto Hari $2.40
by Dergibson Siagian & Sugiarto $13.00
by Hines, William W.K. Dougles E. Montgomery $11.00
by Prof. Dr. Sondang P. Siagian, M.P.A $7.00