WANG, Jintao, LI, Desheng and DUAN, Jinqiao. Compactly generated shape index theory and its application to a retarded nonautonomous parabolic equation. Topological Methods in Nonlinear Analysis. Online. 6 March 2022. Vol. 59, no. 1, pp. 1 - 33. [Accessed 22 July 2024]. DOI 10.12775/TMNA.2021.031.