LUOR, Dah-Chin. On the equivalence of boundedness for multiple Hardy-Littlewood averages and related operators. Mathematica Scandinavica, Berkeley, CA, United States, v. 123, n. 2, p. 273–296, 2018. DOI: 10.7146/math.scand.a-105662. Disponível em: https://journals.msp.org/mscand/article/view/256. Acesso em: 24 jul. 2026.