Korzyuk, Victor, and Olga Kovnatskaya. “Weak Solutions of Boundary Value Problems in Nontube Domains for Fourth-Order Equations of Composite Type”. Mathematical Modelling and Analysis 16, no. 3 (August 24, 2011): 498-508. Accessed December 22, 2024. https://journals.vilniustech.lt/index.php/MMA/article/view/5557.