1.
Nichols R, Hofmann S, Gesztesy F. On square root domains for non-self-adjoint Sturm-Liouville operators. MFAT [Internet]. 2013 Sep. 25 [cited 2025 Dec. 16];19(3):227-59. Available from: https://zen.imath.kiev.ua/index.php/mfat/article/view/550