@article{Antczak:2012,
  author  = "M. Antczak and M. Hromada and P. Tryjanowski",
  title   = "Sex differences in impaling behaviour of Great Grey Shrike Lanius excubitor: Do males have better impaling skills than females?",
  journal = "Behavioural Processes",
  volume  = "Vol. 91",
  number  = "no. 1",
  pages   = "50--53",
  year    = "2012",
}