Lyapunov type inequalities via fractional proportional derivatives and application on the free zero disc of Kilbas-Saigo generalized Mittag-Leffler functions⋆Thabet Abdeljawad, Fahd Jarad, Saed F. Mallak and Jehad AlzabutEur. Phys. J. Plus, 134 5 (2019) 247DOI: https://doi.org/10.1140/epjp/i2019-12772-1