by Sudarwan Danim $7.00
by Drs. Ary H. Gunawan $7.00
by Dra. Zuhairini, dkk $9.00
by FMIPA Universitas Indonesia $6.00
by Dr. Ibrahim Bafadal, M.Pd $7.00
by Drs. Syaiful Bahri Djamarah $7.00