Chabrowski, Jan, and Jianfu Yang. “Sharp Sobolev Inequality Involving a Critical Nonlinearity on a Boundary”. Topological Methods in Nonlinear Analysis 25, no. 1 (March 1, 2005): 135–153. Accessed July 3, 2024. https://apcz.umk.pl/TMNA/article/view/TMNA.2005.006.