Columbia subject headings:
Astrophysics--Congresses.
Measurement--Congresses.
Metrology--Congresses.
Physical constants--Congresses.
Harvard subject headings:
Astrophysics
Astrophysics--Congresses
Measurement--Congresses.
Metrology--Congresses
Physical constants--Congresses.
Physics
Quantum theory
Relativity (Physics)
Weights and measures
Princeton subject headings:
Astrophysics--Congresses.
Measurement--Congresses.
Metrology--Congresses.
Physical constants--Congresses.