by Dennis J. Cahill $9.00
by Drs. Hendrojogi, MSc $11.00
by Prof. K. Ali $6.00
by Nabilah Lubis $5.00
by Huala Adolf $9.00
by Bur Rusuanto $12.00
by American Asociation of State Highway and Transportation Officials $9.00
by Cicely Mary Barker $7.00