WALTER, J. Note on a Paper by Stetkær-Hansen Concerning Essential Selfadjointness of Schroedinger Operators. MATHEMATICA SCANDINAVICA, [S. l.], v. 25, p. 94–96, 1969. DOI: 10.7146/math.scand.a-10943. Disponível em: https://www.mscand.dk/article/view/10943. Acesso em: 6 may. 2024.