Perhaps you should try some spelling variations:
_quality control » quality control, byquality control, quality controls
24 reliability » 2.4 reliability, 4 reliability, 14 reliability
2 reliability » 3 reliability, 5 reliability
2c safety » 25 safety, 21 safety, 24 safety
22 safety » 12 safety, 5 safety, 4 safety
23 safety » 13 safety, 5 safety, 4 safety
2 safety » 5 safety, 4 safety
3 safety » 5 safety, 4 safety

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%((24 reliability) OR (2 reliability))%((((((2c safety) OR (22 safety))) OR (((23 safety) OR (2 safety))))) OR (3 safety)) AND risk%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%_quality control%((24 reliability) or (2 reliability))%((((((2c safety) or (22 safety))) or (((23 safety) OR (2 safety))))) or (3 safety)) and risk%22".
• Adding a wildcard symbol may retrieve word variants: %_quality control%((24 reliability) or (2 reliability))%((((((2c safety) or (22 safety))) or (((23 safety) OR (2 safety))))) or (3 safety)) and risk%22*.