Perhaps you should try some spelling variations:
heilkunde 1991 » heilkunde 11, heilkunde 15.15, heilkunde 10
heilkunde 1 » heilkunde 10, heilkunde 11, heilkunde 16
\"vers.bern.dt.gels.hno- » \"verse.bern.dt.gels.hno-, \"verso.bern.dt.gels.hno-, \"ver.bern.dt.gels.hno-, \"vers.been.dt.gels.hno-, \"vers.ben.dt.gels.hno-, \"vers.bern.dt.gel.hno-, \"vers.bern.dt.gets.hno-
\"verh.born.dt.gels.hno-heilkunde » \"verh.born.dt.gel.hno-heilkunde, \"verh.born.dt.gets.hno-heilkunde, \"ver.born.dt.gels.hno-heilkunde, \"verb.born.dt.gels.hno-heilkunde, \"vera.born.dt.gels.hno-heilkunde
\"very.born.dt.gels.hno-heilkunde » \"very.born.dt.gel.hno-heilkunde, \"very.born.dt.gets.hno-heilkunde
\"verh.born.dt.geld.hno-heilkunde » \"ver.born.dt.geld.hno-heilkunde, \"verb.born.dt.geld.hno-heilkunde, \"vera.born.dt.geld.hno-heilkunde, \"verh.born.dt.gold.hno-heilkunde, \"verh.born.dt.gel.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 1991) OR (heilkunde 1))\") or (((\"verh.born.dt.gels.hno-heilkunde OR \"verh.born.dt.geld.hno-heilkunde) or \"very.born.dt.gels.hno-heilkunde) 1991\"))".
• The words AND, OR and NOT may confuse the search; try adding quotes: "\"((\\"vers.bern.dt.gels.hno-((heilkunde 1991) or (heilkunde 1))\\") or (((\\"verh.born.dt.gels.hno-heilkunde OR \\"verh.born.dt.geld.hno-heilkunde) or \\"very.born.dt.gels.hno-heilkunde) 1991\\"))\"".
• Removing quotes may allow a broader search: (( vers.bern.dt.gels.hno-((heilkunde 1991) or (heilkunde 1)) ) or ((( verh.born.dt.gels.hno-heilkunde OR verh.born.dt.geld.hno-heilkunde) or very.born.dt.gels.hno-heilkunde) 1991 )).