Columbia subject headings:
Paleobotany--Mesozoic--Congresses.
Paleobotany--Mexico--Congresses.
Palynology--Mexico--Congresses.
Plankton, Fossil--Mexico--Congresses.
Pollen, Fossil--Mexico--Congresses.
Harvard subject headings:
Paleobotany--Mexico--Congresses.
Palynology--Mexico--Congresses.
Pollen, Fossil--Mexico--Congresses.
Princeton subject headings: