Barreira, Luis, e Claudia Valls. “Center Manifolds Optimal Regularity for Nonuniformly Hyperbolic Dynamics”. São Paulo Journal of Mathematical Sciences 5, no. 1 (junho 30, 2011): 1-22. Acessado fevereiro 4, 2023. https://www.revistas.usp.br/spjournal/article/view/65.