Puyda, D. V., and Ya. V. Mykytyuk. “On the Accelerants of Non-Self-Adjoint Dirac Operators”. Methods of Functional Analysis and Topology 20, no. 4 (December 25, 2014): 349–364. Accessed December 17, 2025. https://zen.imath.kiev.ua/index.php/mfat/article/view/591.