Feller MN, Belopolskaya YI, Albeverio S. Riquier problem for nonlinear elliptic equations with Lévy Laplacians. MFAT [Internet]. 2005 Mar. 25 [cited 2025 Dec. 16];11(1):1-9. Available from: https://zen.imath.kiev.ua/index.php/mfat/article/view/261