Perhaps you should try some spelling variations:
_quality control » quality control, byquality control, quality controls
5 reliability » 3 reliability
2 reliability » 3 reliability
2c safety » 23 safety, 25 safety, 21 safety
22 safety » 12 safety, 5 safety, 4 safety
2 safety » 5 safety, 4 safety
3 safety » 5 safety, 4 safety

Try widening your search to All Fields.

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: %_quality control%((5 reliability) OR (2 reliability))%((((((2c safety) OR (22 safety))) OR (2 safety))) OR (((3 safety) OR (_ safety)))) AND risk%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%_quality control%((5 reliability) or (2 reliability))%((((((2c safety) OR (22 safety))) or (2 safety))) or (((3 safety) or (_ safety)))) and risk%22".
• Adding a wildcard symbol may retrieve word variants: %_quality control%((5 reliability) or (2 reliability))%((((((2c safety) OR (22 safety))) or (2 safety))) or (((3 safety) or (_ safety)))) and risk%22*.