JANSON, Svante. Characterisations of $H^1$ by singular intetgral transforms on martingales and $\mathsf{R}^n$. Mathematica Scandinavica, Berkeley, CA, United States, v. 41, p. 140–152, 1977. DOI: 10.7146/math.scand.a-11708. Disponível em: https://journals.msp.org/mscand/article/view/1936. Acesso em: 25 jul. 2026.