FOLNER, E. Besicovitch almost periodic functions in arbitrary groups. MATHEMATICA SCANDINAVICA, [S. l.], v. 5, p. 47–53, 1957. DOI: 10.7146/math.scand.a-10488. Disponível em: https://www.mscand.dk/article/view/10488. Acesso em: 5 may. 2024.