by Ir. Rabiatual Adawyah, M.P $7.00
by Dr. Zakiah Daradjat, dkk $11.00
by Tini K $5.00
by William J. Goode $9.00
by Drs. Amin Wijaja Tunggal, M.B.A $11.00
by Prof. Dr. Suharsimi Arikunto $18.00