Baranetskij, Ya.O., I.I. Demkiv, A.V. Solomko, and O.M. Sus’. 2021. “Nonlocal Multipoint Problem for a Differential Equation of $2n$-Th Order With Operator Coefficients”. Carpathian Mathematical Publications 13 (2):501-14. https://doi.org/10.15330/cmp.13.2.501-514.