@article{941416,
      recid = {941416},
      author = {Malling Olsen, Klaus. and Larsson, Hans.},
      title = {Gulls of Europe, Asia and North America [electronic  resource] /},
      publisher = {Christopher Helm,},
      address = {London :},
      pages = {608 p. :},
      year = {2003},
      url = {http://library.usi.edu/record/941416},
}