FOLNER, Erling. Note on groups with and without full Banach mean value. Mathematica Scandinavica, Berkeley, CA, United States, v. 5, p. 5–11, 1957. DOI: 10.7146/math.scand.a-10482. Disponível em: https://journals.msp.org/mscand/article/view/2840. Acesso em: 25 jul. 2026.