by Ressang, A.A $6.00
by DR. Farida Yusuf Tayibnapis, M.Pd $7.00
by Perserikatan Bangsa-Bangsa $7.00
by Prof. Dr. Suharsimi Arikunto, dkk $7.00
by Connel, Des. W. $7.00
by Ir. Moehar Daniel, M.S $7.00