by David A. Wise & Mark Malseed $16.00
by Kurtines, William M. & Jacob L. Gerwitz $11.00
by Robert K. Cooper, Ph.D. Ayman Sawaf $13.00
by Ashadi Siregar & I Made Suarjana $6.00
by Marihot P. Siahaan $16.00
by Miles Matthew B. dan A. Michael Huberman $9.00