Columbia subject headings:
Geology, Stratigraphic--Eocene.
Geology, Stratigraphic--Oligocene.
Paleontology--Eocene.
Paleontology--Oligocene.
Harvard subject headings:
Geology, Stratigraphic--Eocene
Geology, Stratigraphic--Oligocene
Paleontology--Eocene
Paleontology--Oligocene
Princeton subject headings:
Geology, Stratigraphic--Eocene.
Geology, Stratigraphic--Oligocene.
Paleontology--Eocene.
Paleontology--Oligocene.