by Walter L. Wallace $7.00
by Ir. Lisdiana Fachruddin $5.00
by Theo Riyanto, FIC $6.00
by Ir. F.X. Susanto Tumpal HS. Siregar $5.00
by C.M. Lingga Purnama, MM. $9.00
by Leo Suryadinata $4.61