1. I. Podlubny, Fractional differential equations, San Diego: Academic Press, 1999.
2. S. Das, Functional fractional calculus, Berlin, Heidelberg: Springer, 2011. https://doi.org/10.1007/978-3-642-20545-3
3. S. Abbas, M. Benchohra, G. M. N'Guérékata, Topics in fractional differential equations, New York: Springer, 2012. https://doi.org/10.1007/978-1-4614-4036-9
4. A. A. Kilbas, H. M. Srivastava, J. J. Trujillo, Theory and applications of fractional differential equations, Amsterdam: Elsevier, 2006.
5. C. Milici, G. Drăgănescu, J. T. Machado, Introduction to fractional differential equations, Cham: Springer, 2019. https://doi.org/10.1007/978-3-030-00895-6