Columbia subject headings:
Harvard subject headings:
Astronomy--Germany--History--Congresses.
Astronomy--History--17th century--Congresses.
Galilei, Galileo, 1564-1642--Congresses.
Kepler, Johannes, 1571-1630--Congresses.
Telescopes--History--Congresses.
Princeton subject headings:
Astronomy--Germany--History--Congresses.
Galilei, Galileo, 1564-1642--Congresses.
Kepler, Johannes, 1571-1630--Congresses.
Telescopes--History--Congresses.