by $6.00
by Dr. Lijan Poltak Sinambel, M.M., M.Pd., dkk $9.00
by Miller, Connell $9.00
by Drs. Daryanto $7.00
by Drs. Firman B. Aji dan Drs. Martin Sirait $9.00
by Robert Heilbronner $6.00