by Thomas Ballantine Irving $6.00
by Ir. Adiwarman Karim, SE, MBA, MAEP $7.00
by Dr. Nashir bin Sulaiman al-Umr $6.00
by Agus S. Gunadi $7.00
by Dr. Anis Malik Thoha $11.00
by M. Ali Hasan $7.00