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Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 28, No. 1, pp. 12–26, January–February, 1976.
We greatly thank Yu. M. Berezanskii for his interest in this work, and also L. I. Vainerman, A. N. Kochubei, and V. A. Mikhailets for help and friendly discussions.
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Gorbachuk, V.I., Gorbachuk, M.L. Some questions of the spectral theory of differential equations of elliptic type in the space of vector functions on a finite interval. Ukr Math J 28, 9–19 (1976). https://doi.org/10.1007/BF01559222
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DOI: https://doi.org/10.1007/BF01559222