by Ernest Dichter $9.00
by Prof. Dr. Suharsimi Arikunto $11.00
by Prof. Dr. H. Zainuddin Ali, M.A $7.00
by Bambang Sunggono $9.00
by Dr. Sofyan Syafri Harahap, M.S,Ac $7.00
by Prof. Dr. Sudarwan Danim $11.00
by - $9.00
by WK $12.00