Nyamoradi, N., and M. Javidi. “POSITIVE SOLUTIONS FOR FRACTIONAL DIFFERENTIAL EQUATIONS WITH P-LAPLACIAN”. Journal of Nonlinear Analysis and Optimization: Theory & Applications, vol. 3, no. 2, Aug. 2012, pp. 239-53, http://www.math.sci.nu.ac.th/ojs302/index.php/jnao/article/view/171.