Ziemian, Bogdan. “Leray Residue Formula and Asymptotics of Solutions to Constant Coefficient PDEs”. Topological Methods in Nonlinear Analysis 3, no. 2 (June 1, 1994): 257–293. Accessed July 22, 2024. https://apcz.umk.pl/TMNA/article/view/TMNA.1994.014.