GRUBB, Gerd. Exact Green’s formula for the fractional Laplacian and perturbations. Mathematica Scandinavica, Berkeley, CA, United States, v. 126, n. 3, p. 568–592, 2020. DOI: 10.7146/math.scand.a-120889. Disponível em: https://journals.msp.org/mscand/article/view/176. Acesso em: 24 jul. 2026.