Afrouzi, G., Zhang, Q., & Naghizadeh, Z. (2013). BANACH FIXED POINT THEOREM IN APPLICATION TO NONLINEAR ELLIPTIC SYSTEMS. Journal of Nonlinear Analysis and Optimization: Theory & Applications, 4(2), 149-155. Retrieved from http://www.math.sci.nu.ac.th/ojs302/index.php/jnao/article/view/172