Perhaps you should try some spelling variations:
double bounded » doubly bounded, double blinded, doubly bonded
double eyelid » double eged, double eye
double folded » soluble folded, double folding, double rounded
double folio » double folding, double fusion, double poling
helix » felix

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: the ((((double helix) OR (double eyelid))) OR (((double folio) OR (((double folded) OR (double bounded)))))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "the ((((double helix) or (double eyelid))) or (((double folio) or (((double folded) OR (double bounded))))))".
• Adding a wildcard symbol may retrieve word variants: the ((((double helix) or (double eyelid))) or (((double folio) or (((double folded) OR (double bounded))))))*.