“A Maximum Principle for Elliptic and Parabolic Equations with Oblique Derivative Boundary Problems”, J. Part. Diff. Eq., vol. 5, no. 4, pp. 23–27, May 2020, Accessed: Dec. 06, 2025. [Online]. Available: https://www.global-sci.com/index.php/jpde/article/view/3724