Perhaps you should try some spelling variations:
"film producers" » "film producer", "films produced", "ndm producers"
"rice producers" » "co producers", "picture producers"
"food producers" » "food products", "food product", "food process"

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: (((("film producers") OR ("rice producers"))) OR ("food producers")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"film producers\") OR (\"rice producers\"))) or (\"food producers\"))".
• Removing quotes may allow a broader search: (((( film producers ) OR ( rice producers ))) or ( food producers )).
• Adding a wildcard symbol may retrieve word variants: (((("film producers") OR ("rice producers"))) or ("food producers"))*.