@incollection { Tönnies1927,
 title = {Demokratie},
 author = {Tönnies, Ferdinand and Kelsen, Hans},
 pages = {12-68},
 year = {1927},
 publisher = {Mohr Siebeck},
 url = {http://nbn-resolving.de/urn:nbn:de:0168-ssoar-190169},
}