@article{Kraskevitch:1980,
  author  = "V. Kraskevitch and J. Korbicz",
  title   = "Suboptimal Kalman-filter for the distributed parameter systems",
  journal = "Systems Science",
  volume  = "Vol. 6",
  number  = "no 3",
  pages   = "225--234",
  year    = "1980",
}