1.
Faierman M. Fredholm theory connected with a Douglis-Nirenberg system of differential equations over $\mathbb{R}^n$. MFAT [Internet]. 2016 Dec. 25 [cited 2025 Dec. 16];22(4):330-45. Available from: https://zen.imath.kiev.ua/index.php/mfat/article/view/645