Perhaps you should try some spelling variations:
vers.bern.dt.gels.hno-heilkunde » verse.bern.dt.gels.hno-heilkunde, verso.bern.dt.gels.hno-heilkunde, ver.bern.dt.gels.hno-heilkunde, vers.been.dt.gels.hno-heilkunde, vers.bern.dt.geld.hno-heilkunde
vers.ben.dt.gel.hno-heilkunde » verse.ben.dt.gel.hno-heilkunde, verso.ben.dt.gel.hno-heilkunde, ver.ben.dt.gel.hno-heilkunde, vers.been.dt.gel.hno-heilkunde
vera.born.dt.gels.hno-heilkunde » vera.born.dt.geld.hno-heilkunde, ver.born.dt.gels.hno-heilkunde, verb.born.dt.gels.hno-heilkunde
very.born.dt.gels.hno-heilkunde » very.born.dt.geld.hno-heilkunde
very.born.dt.gets.hno-heilkunde » very.born.dt.get.hno-heilkunde

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (( (vers.bern.dt.gels.hno-heilkunde OR vers.ben.dt.gel.hno-heilkunde) 1991 ) OR (( vera.born.dt.gels.hno-heilkunde OR (very.born.dt.gels.hno-heilkunde OR very.born.dt.gets.hno-heilkunde)) 1991 )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( (vers.bern.dt.gels.hno-heilkunde or vers.ben.dt.gel.hno-heilkunde) 1991 ) or (( vera.born.dt.gels.hno-heilkunde or (very.born.dt.gels.hno-heilkunde OR very.born.dt.gets.hno-heilkunde)) 1991 ))".
• Adding a wildcard symbol may retrieve word variants: (( (vers.bern.dt.gels.hno-heilkunde or vers.ben.dt.gel.hno-heilkunde) 1991 ) or (( vera.born.dt.gels.hno-heilkunde or (very.born.dt.gels.hno-heilkunde OR very.born.dt.gets.hno-heilkunde)) 1991 ))*.