by Veithzal Rivai $26.00
by Richard Denny $7.00
by Drs. H. Malayu S.P. Hasibuan $7.00
by Sadono Sukirno $13.00
by Hasbullah $9.00
by Prof. Dr. H. Abuddin Nata, M.A $11.00
by O.S. Eoh, Sh, Ms $5.00
by dr. R.H.H. Nelwan, DSPD $5.00