Topological atlas of the Kowalevski--Yehia gyrostat: analytical results   and topological analysis
  We present a review of the results obtained during the last fifty years in the problem of the motion of a heavy gyrostat under the conditions of the Kowalevski type. Hamad M. Yehia in 1986 has proved that the problem is complete integrable. Since then, a lot of works were devoted to different aspects of integrating this problem and of its topological investigation. The main idea of this work is to prove strictly all the facts of qualitative analysis and to fix different mistakes and inaccuracies. The work was supported by the grants of the RFBR No. 10-01-00043, 10-01-97001, 13-01-97025, and 14-01-00119. 
Mikhail P. Kharlamov, Pavel E. Ryabov, Irina I. Kharlamova, Alexander   Yu. Savushkin, Evgeniy G. Shvedov
nlin.SI math-ph math.MP