KRISTENSEN, L.; PEDERSEN, E. K. The $\mathcal{A}$-Module Structure for the Cohomology of Two-Stage Spaces. MATHEMATICA SCANDINAVICA, [S. l.], v. 30, p. 95–106, 1972. DOI: 10.7146/math.scand.a-11067. Disponível em: https://www.mscand.dk/article/view/11067. Acesso em: 3 may. 2024.