Carbinatto, M. C., and K. P. Rybakowski. “Resolvent Convergence for Laplace Operators on Unbounded Curved Squeezed Domains”. Topological Methods in Nonlinear Analysis, vol. 42, no. 2, Apr. 2013, pp. 233-56, https://apcz.umk.pl/TMNA/article/view/TMNA.2013.035.