by Drs. Daryanto $6.00
by Dr. Ir. H. Suprijanto $9.00
by Prof. Dr. Suharsimi Arikunto $11.00
by Anas Sudijono $11.00
by K. Usman $6.00
by Prof. Dr. Sondang P. Siagian, M.P.A $11.00