by Ir. Arif Hartoyo, M. S $5.00
by Dr. Al. Purwa Hadiwardoyo, MSF $6.00
by Ir. Eddy Afrianto & Ir. Evi Liviawaty $6.00
by Agus S. Gunadi $9.00
by Darmawijaya, St., Pr. $3.00
by N. Edy Soetanto, BE. $5.00