COMFORT, W. W.; HAGER, Anthony W. The Projection Mapping and Other Continuous Functions on a Product Space. Mathematica Scandinavica, Berkeley, CA, United States, v. 28, p. 77–90, 1971. DOI: 10.7146/math.scand.a-11007. Disponível em: https://journals.msp.org/mscand/article/view/2290. Acesso em: 25 jul. 2026.