@article{AndersenUrsin2009,
  author    = {Knud Peter Andersen and Erik Ursin},
  title     = {A multispecies extension to the Beverton and Holt theory of fishing : with accounts of phosphorus circulation and primary production},
  journal   = {Meddelelser fra Danmarks Fiskeri- og Havunders{\o}gelser},
  volume    = {N.S. 7},
  pages     = {319 -- 435},
  year      = {2009},
}