FOLNER, Erling. Note on groups with and without full Banach mean value. MATHEMATICA SCANDINAVICA, [S. l.], v. 5, p. 5–11, 1957. DOI: 10.7146/math.scand.a-10482. Disponível em: https://tidsskrift.dk/math/article/view/10482. Acesso em: 14 aug. 2026.