An asymptotic solution for differential equations in a Banach space in the presence of a finite system of multiple eigenvalues
English version (Springer): Ukrainian Mathematical Journal 28 (1976), no. 5, pp 506-512.
Citation Example: Feshchenko S. F., Sotnichenko N. A. An asymptotic solution for differential equations in a Banach space in the presence of a finite system of multiple eigenvalues // Ukr. Mat. Zh. - 1976. - 28, № 5. - pp. 655–662.
Full text