1. A Caputo fractional derivative of a function with respect to another function
2. M. Caputo, Elasticita e Dissipazione, Zanichelli, Bologna, Italy, 1969.
3. M. Caputo, Mean fractional-order-derivatives differential equations and filters, Ann. Univ. Ferrara 41 (1995), 73–84.
4. Optimality conditions for variational problems involving distributed-order fractional derivatives with arbitrary kernels
5. A. A. Kilbas, H. M. Srivastava and J. J. Trujillo, Theory and Applications of Fractional differential Equa-tions. North-Holland Mathematics Studies, 204. Elsevier Science B.V., Amsterdam, 2006.