by Prof. Dr. Suharsimi Arikunto $11.00
by Drs. Djalinus Syah $7.00
by Michael P. Todaro $16.00
by dr. Moses Wong $7.00
by Glenn A. Welsch, dkk $22.00
by Drs. Daryanto $6.00
by Prof. Dr. Oemar Hamalik $7.00