by Tinbergen, Jan $6.00
by Herris B. Simandjuntak $11.00
by Mohamad Sobary $9.00
by Vincent Gaspersz $18.00
by Baum, Warren C & Stokes M. Tolbert $9.00
by Julius R. Latumaerissa, S.E., M.M $9.00
by Indriani $11.00
by Muhammad Izuddin Taufiq $26.00