by Prof. Dr. Sondang P. Siagian, M.P.A $7.00
by Drs. Amin Widjaja Tunggal, Ak., M.B.A $6.00
by John Salindeho $7.00
by Dr. Vincent Gaspersz $18.00
by Yusuf Mansur $3.65
by Gunawan Wiradi $12.00