Havrylenko, I. (2025). The Jacobi operator and the stability of vertical minimal surfaces in the sub-Riemannian Lie group SL(2,R). Visnyk of V. N. Karazin Kharkiv National University. Ser. Mathematics, Applied Mathematics and Mechanics, 102, 30-47. https://doi.org/10.26565/2221-5646-2025-102-02