Perhaps you should try some spelling variations:
federation reform » generation reforms, education reform, preparation reform
ann conservation » land conservation, aid conservation, plant conservation
supply trace » supply trade
supply case » supply cost, supply chain, supply curve
supply ann » supply a, supply annual, supply chain

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( ((supply trace) or (supply case)) federation reform. ) or ( supply ann conservation efforts. ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( ((supply trace) OR (supply case)) federation reform. ) OR ( supply ann conservation efforts. )).
• Adding a wildcard symbol may retrieve word variants: (( ((supply trace) or (supply case)) federation reform. ) or ( supply ann conservation efforts. ))*.