DELEANU, A.; HILTON, P. J. Some Remarks on General Cohomology Theories. MATHEMATICA SCANDINAVICA, [S. l.], v. 22, p. 227–240, 1968. DOI: 10.7146/math.scand.a-10887. Disponível em: https://tidsskrift.dk/math/article/view/10887. Acesso em: 14 aug. 2026.