by Prof. DR. dr. S.M. Lumbantobing, SpS(K), SpKJ $6.00
by Tarwoto $9.00
by WK $12.00
by Brian J. Sharkey $13.00
by Dr. Muchtaruddin Mansyur $5.00
by WK $11.00
by Herlina Suyati Bachtiar $7.00
by Prof. Dr. H. Abuddin Nata, M.A $11.00