Perhaps you should try some spelling variations:
"migrant agriculture laborers mexico." » "migrant agricultural laborers mexico.", "migrant agriculture power mexico.", "migrant agriculture labor mexico."
"Migrant agricultura laborers Mexico." » "Migrant agricultural laborers Mexico.", "Migrant agricultura canera Mexico.", "Migrant agricultura las Mexico."
migrant agricultura » migrant agricultural

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: (("Migrant agricultura laborers Mexico.") or ("migrant agriculture laborers mexico."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("Migrant agricultura laborers Mexico.") OR ("migrant agriculture laborers mexico.")).
• Removing quotes may allow a broader search: (( Migrant agricultura laborers Mexico. ) or ( migrant agriculture laborers mexico. )).
• Adding a wildcard symbol may retrieve word variants: (("Migrant agricultura laborers Mexico.") or ("migrant agriculture laborers mexico."))*.