[1]
A. V. Kiselev and Y. Ershova, “Trace formulae for graph Laplacians with applications to recovering matching conditions”, MFAT, vol. 18, no. 4, pp. 343–359, Dec. 2012, Accessed: Dec. 16, 2025. [Online]. Available: https://zen.imath.kiev.ua/index.php/mfat/article/view/526