by Prof. drh. Charles Rangga Tabbu, M.Sc., Ph.D $13.00
by Srivastava. UK., GV. Shenoy, SC. Sharma $11.00
by Suryokusumo, Sumaryo $6.00
by Dr. Ir. Muhammad Rasyaf, MS $7.00
by H. Rahmat Rukmana $5.00
by Heilbroner, Robert L $9.00