KRECH, G.; WACHNICKI, E. Approximation by some combinations of the Poisson integrals for Hermite and Laguerre expansions. Annales Universitatis Paedagogicae Cracoviensis Studia Mathematica, [S. l.], v. 12, p. 21–29, 2013. Disponível em: https://studmath.uken.krakow.pl/article/view/13182. Acesso em: 31 oct. 2026.