Perhaps you should try some spelling variations:
_quality control » byquality control, quality controls, qouality control
5 reliability » 3 reliability
2 reliability » 3 reliability
2.4 safety » 1.4 safety, 4.4 safety, 2 safety
24 safety » 2 safety, 14 safety, 22 safety
4 safety » _ safety, a safety
5 safety » _ safety, a 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 control))%((5 reliability) OR (2 reliability))%((((((24 safety) OR (2.4 safety))) OR (4 safety))) OR (5 safety)) AND risk%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%((_quality control) or (quality control))%((5 reliability) or (2 reliability))%((((((24 safety) OR (2.4 safety))) or (4 safety))) or (5 safety)) and risk%22".
• Adding a wildcard symbol may retrieve word variants: %((_quality control) or (quality control))%((5 reliability) or (2 reliability))%((((((24 safety) OR (2.4 safety))) or (4 safety))) or (5 safety)) and risk%22*.