Columbia subject headings:
Astrometry--Congresses.
Astronomy--Charts, diagrams, etc.--Congresses.
Parallax--Observations--Congresses.
Harvard subject headings:
Astrometry--Congresses
Astronomy--Charts, diagrams, etc.--Congresses.
Parallax--Observations--Congresses.
Princeton subject headings:
Astrometry--Congresses.
Astronomy--Charts, diagrams, etc.--Congresses.
Parallax--Observations--Congresses.