SJÖLIN, Per. Maximal operators of Schrödinger type with a complex parameter. Mathematica Scandinavica, Berkeley, CA, United States, v. 105, n. 1, p. 121–133, 2009. DOI: 10.7146/math.scand.a-15109. Disponível em: https://journals.msp.org/mscand/article/view/588. Acesso em: 24 jul. 2026.