KonstantinovO. O. “Two-Term Differential Equations With Matrix Distributional Coefficients”. Ukrains’kyi Matematychnyi Zhurnal 67, no. 5 (May 25, 2015): 625–634. Accessed December 3, 2020. http://umj.imath.kiev.ua/index.php/umj/article/view/2010.