Paukštaitė, Gailė, and Artūras Štikonas. “Green’s Matrices for First Order Differential Systems With Nonlocal Conditions∗”. Mathematical Modelling and Analysis 22, no. 2 (March 18, 2017): 213-227. Accessed May 2, 2024. https://journals.vilniustech.lt/index.php/MMA/article/view/890.