Kaabar, M.K.A., Refice, A., Souid, M.S., Martínez, F., Etemad, S., Siri, Z., Rezapour, S., 2021. Existence and U-H-R Stability of Solutions to the Implicit Nonlinear FBVP in the Variable Order Settings.. https://doi.org/10.3390/math9141693