@TECHREPORT{leifeld2010institutional,
  author = {Leifeld, Philip and Schneider, Volker},
  title = {{Institutional Communication Revisited: Preferences, Opportunity
    Structures and Scientific Expertise in Policy Networks}},
  institution = {Max Planck Institute for Research on Collective Goods},
  year = {2010},
  month = {April},
  type = {Preprint},
  number = {2010/12},
  address = {Bonn},
  url = {http://www.coll.mpg.de/pdf_dat/2010_12online.pdf}
}