by Ir. Abbas Siregar Djarijah & Ir. Harsono Puspowardoyo $5.00
by Andang, Al $6.00
by Dr. Muhammad bin Andurrahman al-Khumayyis $5.00
by Ir. M. Lies Suprapti $6.00
by Ir. Hatta Sunanta, B.Sc., MS $6.00
by Nuim Hidayat, M.Si $7.00