Perhaps you should try some spelling variations:
"charities, voluntary exertions" » "charities, voluntary exertion", "charities, voluntary deductions", "charities, voluntary donations"
"charities, voluntary exercise" » "charities, voluntary exile", "charities, military exercise"

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: (("charities, voluntary exercise") OR ("charities, voluntary exertions")).
• Removing quotes may allow a broader search: (( charities, voluntary exercise ) or ( charities, voluntary exertions )).
• Adding a wildcard symbol may retrieve word variants: (("charities, voluntary exercise") or ("charities, voluntary exertions"))*.