ISBELL, J. R. Spaces without Large Projective Subspaces. MATHEMATICA SCANDINAVICA, [S. l.], v. 17, p. 89–105, 1965. DOI: 10.7146/math.scand.a-10766. Disponível em: https://tidsskrift.dk/math/article/view/10766. Acesso em: 14 aug. 2026.