by Harry Simons $12.00
by Prof. Dr. Suharsimi Arikunto $13.00
by Ir. Doli Siregar, M.Sc., FRICS., SVC $11.00
by Ir. Sujamto $12.00
by Evan Pritchard $7.00
by Amiruddin Syarif, S.H $6.00