@article{Schwarz2011,
  author    = {Wolfgang Schwarz},
  title     = {Compensating tendencies in penalty kick decisions of referees in professional football evidence from the German Bundesliga 1963-2006},
  journal   = {Journal of sports sciences},
  volume    = {29},
  number    = {5},
  pages     = {441 -- 447},
  doi       = {10.1080/02640414.2010.538711},
  year      = {2011},
}