Risteska - Kamcheski, Aleksandra. “GENERALIZATION OF APPLICATION OF FUNDAMENTAL LEMMA OF VARIATIONAL CALCULUS”. Balkan Journal of Applied Mathematics and Informatics 8, no. 1 (June 13, 2025): 19-26. Accessed July 6, 2025. https://js.ugd.edu.mk/index.php/bjami/article/view/7135.