Columbia subject headings:
Clay minerals--Congresses.
Geochemistry--Congresses.
Kerogen--Congresses.
Metamorphic rocks--Congresses.
Harvard subject headings:
Clay minerals--Congresses.
Geochemistry--Congresses
Kerogen--Congresses.
Metamorphic rocks--Congresses.
Princeton subject headings:
Clay minerals--Congresses.
Geochemistry--Congresses.
Kerogen--Congresses.
Metamorphic rocks--Congresses.