WITKOWSKI, A. On Levinson’s inequality. Annales Universitatis Paedagogicae Cracoviensis Studia Mathematica, [S. l.], v. 12, p. 59–67, 2013. Disponível em: https://studmath.uken.krakow.pl/article/view/13184. Acesso em: 31 oct. 2026.