On bi-hamiltonian structure of some integrable systems on so*(4)

We classify all the quadratic Poisson structures on $so^*(4)$ and $e^*(3)$, which have the same foliation by symplectic leaves as the canonical Lie-Poisson tensors. The separated variables for the some of the corresponding bi-integrable systems are constructed.Comment: LaTeX with Amsfonts, 13 pages, corrected typo