Columbia subject headings:
Active galaxies--Spectra--Congresses.
Astronomical spectroscopy--Congresses.
Harvard subject headings:
Active galactic nuclei--Congresses.
Active galaxies--Spectra--Congresses.
Astronomical spectroscopy--Congresses
Emission-line galaxies--Congresses.
Princeton subject headings:
Active galaxies--Congresses.
Emission-line galaxies--Congresses.