LIU, Yang. Semiclassical limit of the spectral decomposition of a Schrödinger operator in one dimension. Mathematica Scandinavica, Berkeley, CA, United States, v. 69, p. 291–306, 1991. DOI: 10.7146/math.scand.a-12381. Disponível em: https://journals.msp.org/mscand/article/view/1292. Acesso em: 24 jul. 2026.