Perhaps you should try some spelling variations:
22quality control » quality control, _quality control, byquality control
2c reliability » 2 reliability, 20 reliability, 24 reliability
5 reliability » 3 reliability
21 safety » 1 safety, 23 safety, 25 safety
11 safety » 10 safety, 5 safety, 4 safety
22 safety » 12 safety, 5 safety, 4 safety
a safety » a safe
2 safety » 5 safety, 4 safety, 3 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: %22quality control%((2c reliability) OR (5 reliability))%((((21 safety) OR (11 safety))) OR (((((22 safety) OR (a safety))) OR (2 safety)))) AND risk%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%22quality control%((2c reliability) or (5 reliability))%((((21 safety) OR (11 safety))) or (((((22 safety) or (a safety))) or (2 safety)))) and risk%22".
• Adding a wildcard symbol may retrieve word variants: %22quality control%((2c reliability) or (5 reliability))%((((21 safety) OR (11 safety))) or (((((22 safety) or (a safety))) or (2 safety)))) and risk%22*.