On classical r -matrix for the Kowalevski gyrostat on so ( 4 ) . Komarov, Igor V., Tsiganov, Andrey V. (2006) SIGMA. Symmetry, Integrability and Geometry: Methods and Applications [electronic only]
On isomorphism of integrable cases of the Euler equations on the bi-Hamiltonian manifolds e ( 3 ) and so ( 4 ) . Tsyganov, A.V. (2004) Zapiski Nauchnykh Seminarov POMI
On the topology of an integrable variant of a nonholonomic Suslov problem Zapiski naucnych seminarov POMI