Columbia subject headings:
Astronomical spectroscopy--Congresses.
Atomic spectroscopy--Congresses.
Plasma spectroscopy--Congresses.
Harvard subject headings:
Astronomical spectroscopy--Congresses
Atomic spectroscopy--Congresses.
Plasma spectroscopy--Congresses.
Princeton subject headings:
Astronomical spectroscopy--Congresses.
Atomic spectroscopy--Congresses.
Plasma spectroscopy--Congresses.