Podgaev, Aleksandr. “Compactness Theorems Connected With Problems With Unknown Boundary”. Mathematical notes of NEFU 28, no. 4 (February 1, 2022): 71-89. Accessed September 13, 2024. https://mzsvfu.ru/index.php/mz/article/view/compactness-theorems-connected-with-problems-with-unknown-boundary.