COUCHOURON, Jean-Francois, KAMENSKII, Mikhail I., MIKHAYLENKO, Boris and NISTRI, Paolo. Periodic bifurcation problems for fully nonlinear neutral functional differential equations via an integral operator approach: the multidimensional degeneration case. Topological Methods in Nonlinear Analysis. Online. 1 December 2015. Vol. 46, no. 2, pp. 631 - 664. [Accessed 22 July 2024]. DOI 10.12775/TMNA.2015.062.