LIU, Y. Scattering and spectral theory for Stark Hamiltonians in one dimension. MATHEMATICA SCANDINAVICA, [S. l.], v. 72, p. 265–297, 1993. DOI: 10.7146/math.scand.a-12448. Disponível em: https://www.mscand.dk/article/view/12448. Acesso em: 6 may. 2024.