Perhaps you should try some spelling variations:
decrease their » increase their (Expand search), decreases the (Expand search)
decrease risk » decreased risk (Expand search), increase risk (Expand search), decrease in (Expand search)
risk decrease » risk decreases (Expand search), risk increase (Expand search), break decrease (Expand search)
their mastery » the mastery (Expand search), their masses (Expand search), their markers (Expand search)
decrease the » decreases the (Expand search), decrease in (Expand search), decrease of (Expand search)
the decrease » to decrease (Expand search), and decrease (Expand search)

You may be able to get more results by adjusting your search query.

• Removing quotes may allow a broader search: (( decrease the decrease NOT decrease ) OR ( decrease risk decrease their mastery ))~.