@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 },
}