Perhaps you should try some spelling variations:
"nature _ opiate users." » "nature _ opiate use.", "nature _ site users."
"nature e society pre." » "nature e society part.", "nature e society pt.", "nature e society pmis.", "nature free society pre.", "nature et society pre.", "nature de society pre.", "nature en society pre."
"nature open society pre." » "nature open society part.", "nature open society pt.", "nature open society pmis.", "capture open society pre.", "natural open society pre.", "nature en society pre."

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: (((("nature e society pre.") OR ("nature open society pre."))) OR ("nature _ opiate users."))~.
• Removing quotes may allow a broader search: (((( nature e society pre. ) or ( nature open society pre. ))) or ( nature _ opiate users. ))~.
• Adding a wildcard symbol may retrieve word variants: (((("nature e society pre.") or ("nature open society pre."))) or ("nature _ opiate users."))*.