Perhaps you should try some spelling variations:
"immigrants agricultural laws mexico." » "migrant agricultural laws mexico.", "immigrants cultural laws mexico.", "immigrants agricultural laborers mexico.", "immigrants agricultural law mexico.", "immigrants agricultural class mexico.", "immigrants agricultural blacks mexico."
"immigrants cultura labor mexico." » "immigrants cultural labor mexico.", "immigrants cuba labor mexico.", "migrantes culturas labor mexico.", "immigrants cultura laboral mexico.", "immigrants cultura la mexico.", "immigrants cultura las mexico."

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("immigrants cultura labor mexico.") or ("immigrants agricultural laws mexico."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("immigrants cultura labor mexico.") OR ("immigrants agricultural laws mexico.")).
• Removing quotes may allow a broader search: (( immigrants cultura labor mexico. ) or ( immigrants agricultural laws mexico. )).
• Adding a wildcard symbol may retrieve word variants: (("immigrants cultura labor mexico.") or ("immigrants agricultural laws mexico."))*.