by Karyawan Perangin angin $6.00
by Drs. Suwarna Pringgawidagda, M.Pd $18.00
by Tony Buzan $16.00
by Prof. DR. K.H. Didin Hafidhuddin $12.00
by Dr. Nur Syam $11.00
by Kartini Kartono $7.00