1.
BALANOV, Zolman, KRAWCEWICZ, Wiesław and STEINLEIN, Heinrich. $SO(3)\times S^1$-equivariant degree with applications to symmetric bifurcation problems: the case of one free parameter. Topological Methods in Nonlinear Analysis. Online. 1 December 2002. Vol. 20, no. 2, pp. 335 - 374. [Accessed 6 July 2025].