by Drs. S. Margono $9.00
by Asiyanto $6.00
by Drs. Slameto $7.00
by Srivastava. UK., GV. Shenoy, SC. Sharma $11.00
by Parakkasi, Aminuddin $6.00
by Dr. Hamzah B. Uno, M.Pd $9.00