by Drs. Muchdarsyah Sinungan $9.00
by Prof. Dr. Sondang P. Siagian, M.P.A $11.00
by Radiks Purba $12.00
by Richard G. Lipsey & Peter O. Steiner $18.00
by Michael Rush & Philip Althoff $11.00
by $9.00
by Andi Hamzah $0.00