COUCHOURON, J.-F.; KAMENSKII, M. I.; MIKHAYLENKO, B.; NISTRI, P. Periodic bifurcation problems for fully nonlinear neutral functional differential equations via an integral operator approach: the multidimensional degeneration case. Topological Methods in Nonlinear Analysis, [S. l.], v. 46, n. 2, p. 631–664, 2015. DOI: 10.12775/TMNA.2015.062. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.2015.062. Acesso em: 27 jan. 2022.