@InProceedings{Witczak:2001,
  author      = "M. Witczak and J. Korbicz",
  title       = "An extended unknown input observer for nonlinear discrete-time systems",
  booktitle   = "European Control Conference - ECC '01",
  address     = "Porto, Portugalia",
  publisher   = "Porto, [brak wydawcy]",
  pages       = "[6] CD-ROM",
  organization = "Associacao Portuguesa de Controlo Automatico",
  year        = "2001",
}