Columbia subject headings:
Bilingualism--Mexico.
Indians of Mexico--Commerce.
Otomi Indians--Commerce.
Otomi language--Social aspects.
Spanish language--Social aspects.
Harvard subject headings:
Bilingualism--Mexico.
Indians of Mexico--Commerce.
Otomi Indians--Commerce.
Otomi language--Social aspects.
Spanish language--Social aspects.
Princeton subject headings:
Bilingualism--Mexico.
Indians of Mexico--Commerce.
Otomi Indians--Commerce.
Otomi language--Social aspects.
Spanish language--Social aspects.