A. V. Belyaev, “On the full list of
finite-valued solutions of the Euler-Poisson equations having four
first integrals”, Mathematische Nachrichten, 285:10 (2012), 1199–1229
A. V. Belyaev, “O pryamom dokazatelstve teoremy Puankare
ob invariantnykh torakh”, Ukraїnskii matematichnii visnik, 8:3 (2011), 343–355