Perhaps you should try some spelling variations:
22quality control » quality control, byquality control, forquality control
_quality control » quality control, byquality control, quality controls
9 reliability » 3 reliability, 5 reliability, 2 reliability
safe » same

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))%9 reliability%a safe AND risk%22.
• Adding a wildcard symbol may retrieve word variants: %((22quality control) or (_quality control))%9 reliability%a safe and risk%22*.