by Ketut Rindjin $7.00
by Prof. Dr. Sondang P. Siagian, M.P.A $7.00
by Sprent, P. $7.00
by Jack Trout dan Steven Rivkin $6.00
by Richard Burton Simatupang, S.H $12.00
by Datje Rahajoekoesoemah $28.00