Perhaps you should try some spelling variations:
_quality control » quality control, byquality control, qouality control
quality controls » quality control, qualite controle, quality concepts
2c reliability » 20 reliability, 24 reliability, 29 reliability
ic reliability » 5 reliability, 7 reliability, 8 reliability
2 reliability » 3 reliability, 5 reliability
22 safety » 12 safety, 5 safety, 4 safety
21 safety » 11 safety, 1 safety, 2.4 safety
25 safety » 5 safety, 15 safety, 4 safety
23 safety » 3 safety, 13 safety, 5 safety
24 safety » 2.4 safety, 4 safety, 14 safety
2 safety » 5 safety, 4 safety, 3 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) OR (quality controls))%((((2c reliability) OR (2 reliability))) OR (ic reliability))%((((((((21 safety) OR (25 safety))) OR (24 safety))) OR (22 safety))) OR (((23 safety) OR (2 safety)))) AND risk%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%((_quality control) OR (quality controls))%((((2c reliability) or (2 reliability))) or (ic reliability))%((((((((21 safety) or (25 safety))) or (24 safety))) or (22 safety))) or (((23 safety) or (2 safety)))) and risk%22".
• Adding a wildcard symbol may retrieve word variants: %((_quality control) OR (quality controls))%((((2c reliability) or (2 reliability))) or (ic reliability))%((((((((21 safety) or (25 safety))) or (24 safety))) or (22 safety))) or (((23 safety) or (2 safety)))) and risk%22*.