Perhaps you should try some spelling variations:
mexicanos » mexicana, mexicanas, mexicos
mexicano » mexicana, mexico
americano » americans, americana, americains
americanos » americanss, americanas, americainss, americans, americanus, americas

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: (((mexicanos OR (mexicano OR americano)) OR (americanos OR american)) OR mexican) / united states.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((mexicanos or (mexicano or americano)) or (americanos OR american)) or mexican) / united states".
• Adding a wildcard symbol may retrieve word variants: (((mexicanos or (mexicano or americano)) or (americanos OR american)) or mexican) / united states*.