Boichuk О. A. and Pokutnyi О. О., “Application of the ergodic theory to the investigation of a boundaryvalue problem with periodic operator coefficient”, Ukr. Mat. Zhurn., vol. 65, no. 3, pp. 329–338, Mar. 2013, Accessed: Dec. 05, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/2422