@article{Maciejewski:2001,
  author  = "A. Maciejewski and S. Popov and J. Strelcyn",
  title   = "The Euler equations on Lie algebra so(4): an elementary approach to integrability condition",
  journal = "Journal of Mathematical Physics",
  volume  = "Vol. 42",
  number  = "no 6",
  pages   = "2701--2717",
  year    = "2001",
}