Perhaps you should try some spelling variations:
verh.been.dt.gels.hno-heilkunde » ver.been.dt.gels.hno-heilkunde, vers.been.dt.gels.hno-heilkunde, vera.been.dt.gels.hno-heilkunde, verh.been.dt.gel.hno-heilkunde, verh.been.dt.geld.hno-heilkunde
verh.born.dt.gels.hno-heilkunde » ver.born.dt.gels.hno-heilkunde, vers.born.dt.gels.hno-heilkunde, vera.born.dt.gels.hno-heilkunde, verh.born.dt.gel.hno-heilkunde, verh.born.dt.geld.hno-heilkunde
verh.born.dt.gets.hno-heilkunde » ver.born.dt.gets.hno-heilkunde, vers.born.dt.gets.hno-heilkunde, vera.born.dt.gets.hno-heilkunde, verh.born.dt.get.hno-heilkunde
verb.been.dt.gels.hno-heilkunde » verb.been.dt.gel.hno-heilkunde, verb.been.dt.geld.hno-heilkunde, ver.been.dt.gels.hno-heilkunde, vers.been.dt.gels.hno-heilkunde
very.born.dt.gels.hno-heilkunde » very.born.dt.gel.hno-heilkunde, very.born.dt.geld.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: (( (verh.been.dt.gels.hno-heilkunde OR verb.been.dt.gels.hno-heilkunde) 1991 ) OR (( (verh.born.dt.gels.hno-heilkunde OR verh.born.dt.gets.hno-heilkunde) OR very.born.dt.gels.hno-heilkunde) 1991 )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( (verh.been.dt.gels.hno-heilkunde OR verb.been.dt.gels.hno-heilkunde) 1991 ) or (( (verh.born.dt.gels.hno-heilkunde or verh.born.dt.gets.hno-heilkunde) or very.born.dt.gels.hno-heilkunde) 1991 ))".
• Adding a wildcard symbol may retrieve word variants: (( (verh.been.dt.gels.hno-heilkunde OR verb.been.dt.gels.hno-heilkunde) 1991 ) or (( (verh.born.dt.gels.hno-heilkunde or verh.born.dt.gets.hno-heilkunde) or very.born.dt.gels.hno-heilkunde) 1991 ))*.