Perhaps you should try some spelling variations:
"open resource depletion" » "open resource selection", "open resource description", "open reresources depletion", "open reresource repletion", "open resurface depletion", "open resources depletion", "ocean resource depletion", "open sources depletion"
"open source depletion" » "open resources depletion", "open resource repletion", "open surface depletion"

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"open resource depletion\") OR (\"open source depletion\"))".
• Removing quotes may allow a broader search: (( open resource depletion ) OR ( open source depletion )).
• Adding a wildcard symbol may retrieve word variants: (("open resource depletion") OR ("open source depletion"))*.