Salim ABDELKRİM, Mouffak BENCHOHRA, Jamal Eddine LAZREG, Johnny HENDERSON
Advances in the Theory of Nonlinear Analysis and its Application
173-190
$\psi$-Hilfer fractional derivative, $k$-generalized $\psi$-Hilfer fractional derivative, Cauchy-type problem, retarded arguments, advanced arguments, existence, uniqueness