WAHASH , H. A., ABDO , M. S., PANCHAL , S. K., & BHAIRAT, S. P. (2021). Existence of solution for Hilfer fractional differential problem with nonlocal boundary condition. Studia Universitatis Babeș-Bolyai Mathematica, 66(3), 521–536. https://doi.org/10.24193/subbmath.2021.3.09