by Prof. Drs. H.A.W. Widjaja $7.00
by Adler Haymans Manurung $7.00
by - $11.00
by M. Aleq Sander, S.Dr $22.00
by Prof. Dr. Sondang P. Siagian, M.P.A $7.00
by Baum, Warren C & Stokes M. Tolbert $7.00
by Dr. R. Paryana Suryadipura $12.00