by Ir. Pracaya $6.00
by Agus DS $7.00
by Ir. F.X. Susanto Tumpal HS. Siregar $5.00
by Ir. L. Widarto & FX. Sudarto C. Ph $5.00
by Ir. H. Rahmat Rukmana $6.00
by J. Donald Walters $3.00