Kvant magazine archive with solved physics and mathematics problems from decades of publication.
A portal with Russian-language physics problems, materials, and worked solutions.
Site with worked solutions to Irodov, Chertov-Vorobyov, Savelyev, Volkenshtein, and Meshchersky physics problem books.
A site collecting solutions to classic Soviet-era problem books used in physics olympiad and entrance exam preparation.
A Russian site providing solutions to both Chertov-Vorobyov and Savelyev problem collections.