by Drs. Tjahya Supriatna, M.S $9.00
by Drs. Syaiful Bahri Djamarah $9.00
by Drs. I Nyoman Beratha $7.00
by Prof. Dr. Suharsimi Arikunto $18.00
by Prof. Dr. S. Nasution, M.A. $7.00
by Prof. Dr. Sukardi, Ph.D $9.00