by Prof. H.M. Arifin, M.Ed $9.00
by Drs. Amin Wijaja Tunggal, M.B.A $11.00
by Eko P. Pratomo $12.00
by Prof. Dr. Sondang P. Siagian, M.P.A $7.00
by Hendri F. Isnaeni $4.32
by $16.00