LIU, Yang. Scattering and spectral theory for Stark Hamiltonians in one dimension. Mathematica Scandinavica, Berkeley, CA, United States, v. 72, p. 265–297, 1993. DOI: 10.7146/math.scand.a-12448. Disponível em: https://journals.msp.org/mscand/article/view/1176. Acesso em: 25 jul. 2026.