Cosmos posts a long biographical retrospective from Stephen Hawking about his life and work. A lot of it will be review for people well-read on the history of cosmology -- but I hadn't realized this:
However, two Russians, Lifshitz and Khalatnikov, had claimed to have proved that a general contraction without exact symmetry would always lead to a bounce, with the density remaining finite.
This result was very convenient for Marxist-Leninist dialectical materialism because it avoided awkward questions about the creation of the universe. It therefore became an article of faith for Soviet scientists.