by I. Wibowo $11.00
by Drs. Zainal Abidin $7.00
by Prof. Dr. Sudarwan Danim $11.00
by Drs. Marcel Go, M.S $7.00
by Prof. Dr. H. Abdurrahmat Fathoni, M.Si $6.00
by Drs. Daryanto $6.00