Columbia subject headings:
Astronomical instruments--Congresses.
Chemical apparatus--Congresses.
Optical instruments--Congresses.
Physical instruments--Congresses.
Spectrum analysis--Congresses.
Harvard subject headings:
Princeton subject headings:
Analytical chemistry--Technique--Congresses.
Astronomy--Technique--Congresses.
Physics--Technique--Congresses.
Spectrum analysis--Instruments--Congresses.