V. I. Mogilevskii, “Symmetric extensions of symmetric linear relations (operators) preserving the multivalued part”, MFAT, vol. 24, no. 2, pp. 152–177, Jun. 2018, Accessed: Feb. 04, 2026. [Online]. Available: https://zen.imath.kiev.ua/index.php/mfat/article/view/692