GRUBB, G. Exact Green’s formula for the fractional Laplacian and perturbations. MATHEMATICA SCANDINAVICA, [S. l.], v. 126, n. 3, p. 568–592, 2020. DOI: 10.7146/math.scand.a-120889. Disponível em: https://www.mscand.dk/article/view/120889. Acesso em: 2 oct. 2022.