SJÖLIN, P. Nonlocalization of operators of Schrödinger type. Annales Fennici Mathematici, [S. l.], v. 38, n. 1, p. 141–147, 2013. DOI: 10.5186/aasfm.2013.3805. Disponível em: https://afm.journal.fi/article/view/135427. Acesso em: 27 apr. 2025.