@inproceedings{sgem2013s20142,
  title = {THE UPPER VISTULA VALLEY NATURA 2000 AREA   A KEY ELEMENT OF THE MOST IMPORTANT ECOLOGICAL CORRIDOR IN CENTRAL EUROPE},
  author = {Jacek Betleja},
  booktitle = {SGEM International Multidisciplinary Scientific GeoConference EXPO Proceedings; 13th SGEM GeoConference on ECOLOGY, ECONOMICS, EDUCATION AND LEGISLATION},
  year = {2013},
  pages = {},
  publisher = {Stef92 Technology},
  doi = {10.5593/sgem2013/be5.v1/s20.142}
}