Makhnei, O.V. “Asymptotics of a Fundamental Solution System for a Quasidifferential Equation With Measures on the Semiaxis”. Carpathian Mathematical Publications 6, no. 1 (July 15, 2014): 113–122. Accessed May 5, 2024. https://journals.pnu.edu.ua/index.php/cmp/article/view/1342.