Supplemental Material, 2019-03-22_suppl_material - Explaining the patterns of contacts between interest groups and political parties: Revising the standard model for populist times

Supplemental Material, 2019-03-22_suppl_material for Explaining the patterns of contacts between interest groups and political parties: Revising the standard model for populist times by Joost Berkhout, Marcel Hanegraaff and Patrick Statsch in Party Politics