Columbia subject headings:
Aztec calendar.
Indian astronomy--Central America.
Indian astronomy--Mexico.
Maya calendar.
Harvard subject headings:
Aztec calendar.
Indian astronomy--Central America
Indian astronomy--Mexico
Maya calendar.
Princeton subject headings:
Central America--Antiquities.
Indian astronomy--Central America.
Indian astronomy--Mexico.
Indian calendar--Central America.
Indian calendar--Mexico.
Indians of Central America--Antiquities.
Indians of Mexico--Antiquities.
Mexico--Antiquities.