Berger, Melvyn S., Martin Schechter, and Guozhang Sun. “Infinite-Dimensional Singularity Theory and Bifurcation from Equilibria for Certain Nonlinear Evolution Equations”. Topological Methods in Nonlinear Analysis 4, no. 2 (December 1, 1994): 341–353. Accessed July 22, 2024. https://apcz.umk.pl/TMNA/article/view/TMNA.1994.032.