Columbia subject headings:
Astronomers--Poland--Biography.
Astronomy--History--Sources.
Copernicus, Nicolaus, 1473-1543.
Harvard subject headings:
Astronomers--Poland--Biography
Astronomy--History--Sources.
Copernicus, Nicolaus, 1473-1543.
Princeton subject headings:
Astronomers--Poland--Biography.
Astronomy--History--Sources.
Copernicus, Nicolaus, 1473-1543.