@article{Verheijen:2010zr,
  author = "Verheijen, Marc A.W.  and  Oosterloo, Tom  and  Heald, George  and  van Cappellen, Wim",
  title = "{HI Surveys with APERTIF}",
  doi = "10.22323/1.089.0010",
  journal = "PoS",
  year = 2010,
  volume = "PRA2009",
  pages = "010"
}