@article{abbas_ragusa_2021, title={On the Hybrid Fractional Differential Equations with Fractional Proportional Derivatives of a Function with Respect to a Certain Function}, volume={13}, DOI={10.3390/sym13020264}, abstractNote={This paper deals with a new class of hybrid fractional differential equations with fractional proportional derivatives of a function with respect to a certain continuously differentiable and increasing function ϑ. By means of a hybrid fixed point theorem for a product of two operators, an existence result is proved. Furthermore, the sufficient conditions of the continuous dependence on the given parameters are investigated. Finally, a simulative example is given to highlight the acquired outcomes.}, publisher={MDPI AG}, author={Abbas, Mohamed I. and Ragusa, Maria Alessandra}, year={2021}, month={Feb} }