Perhaps you should try some spelling variations:
les troubles » des troubles, less trouble, late troubles
les doubles » test doubles, les douanes, les doutes
1991 ibf » 1991 iee, 1991 iv, 1991 im
1991 ii » 1991 bis

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: ((1991 ibf) OR (1991 ii)) ((world championships) OR (world championship)) – ((les doubles) OR (les troubles)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((1991 ibf) or (1991 ii)) ((world championships) or (world championship)) – ((les doubles) OR (les troubles))".
• Adding a wildcard symbol may retrieve word variants: ((1991 ibf) or (1991 ii)) ((world championships) or (world championship)) – ((les doubles) OR (les troubles))*.