Columbia subject headings:
Alluvium--Congresses.
Conglomerate--Congresses.
Gravel--Congresses.
Sedimentation and deposition--Congresses.
Harvard subject headings:
Alluvium--Congresses.
Conglomerate--Congresses.
Gravel--Congresses.
Sedimentation and deposition--Congresses.
Sedimentology--Congresses.
Princeton subject headings:
Alluvium--Congresses.
Conglomerates--Congresses.
Gravel--Congresses.
Sedimentation and deposition--Congresses.