Columbia subject headings:
Glass manufacture--History--Congresses.
Glassware, Ancient--Congresses.
Pottery, Ancient--Congresses.
Silica, Vitreous--Congresses.
Harvard subject headings:
Analytical chemistry--Congresses
Glass manufacture--Congresses.
Glass--Analysis--Congresses.
Glass--Research--Congresses.
Silica, Vitreous--Congresses.
Princeton subject headings: