FÉLIX, Yves; HALPERIN, Steve. The depth and LS category of a topological space. Mathematica Scandinavica, Berkeley, CA, United States, v. 123, n. 2, p. 220–238, 2018. DOI: 10.7146/math.scand.a-106920. Disponível em: https://journals.msp.org/mscand/article/view/254. Acesso em: 24 jul. 2026.