Perhaps you should try some spelling variations:
integration efforts » international efforts, conservation efforts
population census » population density, population densities
poor population » world population
supply trade » supply side, supply case
survey poor » survey labor

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( survey poor population census. ) or ( supply trade integration efforts. ))~.
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