@incollection { Opp1976,
 title = {Der verhaltenstheoretische Ansatz},
 author = {Opp, Karl-Dieter},
 editor = {Lepsius, M. Rainer},
 pages = {60-69},
 year = {1976},
 publisher = {Ferdinand Enke},
 isbn = {3-432-88471-0},
 url = {http://nbn-resolving.de/urn:nbn:de:0168-ssoar-160728},
}