1.
WEBER, Joa. Classical Morse theory revisited - I backward $\lambda$-lemma and homotopy type. Topological Methods in Nonlinear Analysis. Online. 1 June 2016. Vol. 47, no. 2, pp. 641 - 646. [Accessed 3 July 2024]. DOI 10.12775/TMNA.2016.020.