In this paper the sufficient conditions on the existence and uniqueness of a generalized solution on the axis are obtained for higher order operator-differential equations, the main part of which is multi characteristic.
GUMBATALIEV, ROVSHAN Z. (2008) "On Generalized Solution of a Class of Higher Order Operator-Differential Equations," Turkish Journal of Mathematics: Vol. 32: No. 3, Article 5. Available at: https://journals.tubitak.gov.tr/math/vol32/iss3/5