Columbia subject headings:
Celestial mechanics--Congresses.
Copernicus, Nicolaus, 1473-1543--Congresses.
Harvard subject headings:
Celestial mechanics--Congresses
Copernicus, Nicolaus, 1473-1543--Congresses.
Princeton subject headings:
Celestial mechanics--Congresses.
Copernicus, Nicolaus, 1473-1543--Congresses.