by Prof. Dr. Sondang P. Siagian, M.P.A $11.00
by Sulistyowati Irianto, Lim Sing Meij, Firliana Purwanti $9.00
by Drs. Marcel Go, M.S $7.00
by Rhenald Kasali, Ph.D $20.00
by Ratna Batara Munti $7.00
by $5.00