MATHER, Michael. Hurewicz Theorems for Pairs and Squares. Mathematica Scandinavica, Berkeley, CA, United States, v. 32, p. 269–272, 1973. DOI: 10.7146/math.scand.a-11462. Disponível em: https://journals.msp.org/mscand/article/view/2148. Acesso em: 25 jul. 2026.