Perhaps you should try some spelling variations:
2c reliability » 2 reliability, 20 reliability, 24 reliability
ic reliability » 5 reliability, 2 reliability, 7 reliability
2c safety » 23 safety, 25 safety, 24 safety
21 safety » 11 safety, 1 safety, 23 safety
22 safety » 5 safety, 4 safety, 3 safety
12 safety » 11 safety, 1 safety, 5 safety
10 safety » 5 safety, 4 safety, 3 safety
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: %quality control%((2c reliability) OR (ic reliability))%((((((((2c safety) OR (21 safety))) OR (22 safety))) OR (2 safety))) OR (((12 safety) OR (10 safety)))) AND risk%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%quality control%((2c reliability) or (ic reliability))%((((((((2c safety) OR (21 safety))) or (22 safety))) or (2 safety))) or (((12 safety) or (10 safety)))) and risk%22".
• Adding a wildcard symbol may retrieve word variants: %quality control%((2c reliability) or (ic reliability))%((((((((2c safety) OR (21 safety))) or (22 safety))) or (2 safety))) or (((12 safety) or (10 safety)))) and risk%22*.