@Article{Petal:BOI-2009,
  author = 	 {T. Poranen and V. Dagiene and A. Eldhuset and H. Hyyro and 
                  M. Kubica and A. Laaksonen and M. Opmanis and W. Pohl and 
		  J. Skupiene and P Soderhjelm and A. Truu},
  title = 	 {Baltic Olympiads in Informatics: Challenges for Training Together},
  journal = 	 {Olympiads in Informatics},
  year = 	 {2009},
  volume =	 {3},
  pages =	 {112--131}
}