de Sousa, Robert, Feliz Minhós, and João Fialho. “On Coupled Systems of Lidstone-Type Boundary Value Problems”. Mathematical Modelling and Analysis 26, no. 3 (July 13, 2021): 358-371. Accessed December 5, 2021. https://journals.vgtu.lt/index.php/MMA/article/view/12977.