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