Columbia subject headings:
Families--Mexico--Case studies.
Mexico--Social conditions.
Poor--Mexico--Mexico City--Biography.
Poor--Mexico--Mexico City.
Harvard subject headings:
Families--Mexico--Case studies.
Mexico--Social conditions
Poor--Mexico--Mexico City--Biography.
Poor--Mexico--Mexico City.
Princeton subject headings:
Families--Mexico--Case studies.
Mexico--Social conditions.
Poor--Mexico--Mexico City.