by M. Nasib ar-Rifa\'i $28.00
by John Gottman, Ph.D. $9.00
by Prof. I. R. Poedjawijatna $6.00
by Sumarti M. Thahir $5.00
by Ir. Bambang Cahyono $6.00
by Drs. H. Abu Ahmadi $11.00