Columbia subject headings:
Harvard subject headings:
Amateur astronomy--History--Congresses.
Astrology, Oriental--History--Congresses.
Astronomy
Astronomy--History--Congresses.
Islamic astronomy--History--Congresses.
Physics
Science--History
Princeton subject headings:
Amateur astronomy--History--Congresses.
Astrology, Oriental--History--Congresses.
Astronomy--History--Congresses.
Islamic astronomy--History--Congresses.