Columbia subject headings:
Harvard subject headings:
America--Antiquities--Congresses.
Glacial epoch--America--Congresses.
Indians--Origin--Congresses.
Paleo-Indians--Congresses.
Princeton subject headings:
America--Antiquities--Congresses.
Glacial epoch--America--Congresses.
Paleo-Indians--Congresses.
Paleontology--America--Pleistocene--Congresses.