2009-06-242009-06-2419910013-1954urn:nbn:de:hebis:34-2009062428379http://hdl.handle.net/123456789/20090624283791667161 bytesapplication/pdfengUrheberrechtlich geschützthttps://rightsstatements.org/page/InC/1.0/510Preformal proving: examples and reflectionsAufsatz