Perhaps you should try some spelling variations:
"immigrants agricultural labor mexico." » "migrant agricultural labor mexico.", "immigrants cultural labor mexico.", "migrant agriculturall labor mexico.", "immigrants culturall labor mexico.", "immigrants agricultural laborers mexico.", "immigrants agricultural laws mexico.", "immigrants agricultural law mexico."
"immigrants agricultura caso mexico." » "migrant agricultural caso mexico.", "immigrants cultural caso mexico.", "immigrants agricultura como mexico.", "immigrants agricultura las mexico.", "immigrants agricultura tasa mexico.", "immigrants agricultura caso mexicano.", "immigrants agricultura bajio mexico.", "immigrants agricultura culto 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 agricultural labor mexico.") or ("immigrants agricultura caso mexico."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("immigrants agricultural labor mexico.") OR ("immigrants agricultura caso mexico.")).
• Removing quotes may allow a broader search: (( immigrants agricultural labor mexico. ) or ( immigrants agricultura caso mexico. )).
• Adding a wildcard symbol may retrieve word variants: (("immigrants agricultural labor mexico.") or ("immigrants agricultura caso mexico."))*.