[1]
M. Faierman, “Fredholm theory connected with a Douglis-Nirenberg system of differential equations over $\mathbb{R}^n$”, MFAT, vol. 22, no. 4, pp. 330–345, Dec. 2016, Accessed: Dec. 16, 2025. [Online]. Available: https://zen.imath.kiev.ua/index.php/mfat/article/view/645