WAHLBERG, Patrik. Propagation of polynomial phase space singularities for Schrödinger equations with quadratic Hamiltonians. Mathematica Scandinavica, Berkeley, CA, United States, v. 122, n. 1, p. 107–140, 2018. DOI: 10.7146/math.scand.a-97187. Disponível em: https://journals.msp.org/mscand/article/view/290. Acesso em: 24 jul. 2026.