1. Samko, S. G., Kilbas, A. A., Marichev. O. I. Integrals and Derivatives of Fractional Orders with Applications (Nauka i tekhnika, Minsk, 1987) [in Russian].
2. Nakhushev, A. I. Fractional Calculus with Applications (Fizmatgiz, Moscow, 2003) [in Russian].
3. Nakhushev, A. I. Boundary-Value Problems with Shifts for Equations with Partial Derivatives (Nauka, Moskow, 2006) [in Russian].
4. Repin, O. A., Kumykova, S. K. “On a Boundary Value Problem with Shift for an Equation ofMixed Type in an Unbounded Domain”, Differ. Equ. 48, No. 8, 1127–1136 (2012).
5. Repin, O. A., Kumykova, S. K. “Nonlocal Problem for an Equation of Mixed type in a Domain Whose Elliptic Part is a Half-Strip”, Differ. Equ. 50, No. 6, 805–814 (2014).