by Drs. Wasty Soemanto, M.Pd $6.00
by John Adair $9.00
by Lachman, L., Herbert A. Lieberman & Joseph L. Kanig $11.00
by Aziz Alimul $11.00
by Abdul Munir Mulkhan $7.00
by dr. Benhard Rudyanto Sinaga, SpKJ $9.00