by Prof. Dr. Sondang P. Siagian, M.P.A
$11.00

by Dra. Nurul Zuriah, M.Si
$0.00

by Ir. Hieronymus Budi Santoso
$5.00

by Ir. Abbas Siregar Djarijah
$6.00

by Drs. Jumingan, S.E., M.M., M.Si
$11.00

by WK
$12.00