Fomenko A.T., Nikolaenko S.S., “The Chaplygin Case in Dynamics of a Rigid Body in Fluid Is Orbitally Equivalent To the Euler Case in Rigid Body Dynamics and To the Jacobi Problem About Geodesics on the Ellipsoid”, J. Geom. Phys., 87 (2015), 115–133
Papadopoulos G., Dullin H.R., “Semi-Global Symplectic Invariants of the Euler TOP”, J. Geom. Mech., 5:2 (2013), 215–232
A. V. Bolsinov, A. T. Fomenko, Integrable Geodesic Flows on Two-Dimensional Surfaces, 2000, 287