Perhaps you should try some spelling variations:
heilkunde 1991 » heilkunde 11, heilkunde 15.15, heilkunde 1
vers.bern.dt.geld.hno-heilkunde » verse.bern.dt.geld.hno-heilkunde, verso.bern.dt.geld.hno-heilkunde, ver.bern.dt.geld.hno-heilkunde, vers.been.dt.geld.hno-heilkunde, vers.ben.dt.geld.hno-heilkunde, vers.bern.dt.gold.hno-heilkunde
vera.born.dt.gels.hno-heilkunde » ver.born.dt.gels.hno-heilkunde, verb.born.dt.gels.hno-heilkunde
vera.born.dt.gel.hno-heilkunde » ver.born.dt.gel.hno-heilkunde, verb.born.dt.gel.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.geld.hno-heilkunde 1991 ) OR (( (vera.born.dt.gels.hno-heilkunde OR vera.born.dt.gel.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.geld.hno-heilkunde 1991 ) or (( (vera.born.dt.gels.hno-heilkunde OR vera.born.dt.gel.hno-heilkunde) or very.born.dt.gets.hno-heilkunde) 1991 ))".
• Adding a wildcard symbol may retrieve word variants: (( vers.bern.dt.geld.hno-heilkunde 1991 ) or (( (vera.born.dt.gels.hno-heilkunde OR vera.born.dt.gel.hno-heilkunde) or very.born.dt.gets.hno-heilkunde) 1991 ))*.