Reference Label	Details
NSRDS-NBS 35	C. E. Moore, "Atomic Energy Levels", NBS Circular 467, Vols. I through III, National Bureau of Standards: Washington, DC 1949-1958 C. E. Moore, "Atomic Energy Levels", NBS Circular 467, Vol. I, National Bureau of Standards: Washington, DC 1949; C. E. Moore, "Atomic Energy Levels", NBS Circular 467, Vol. II, National Bureau of Standards: Washington, DC 1952; C. E. Moore, "Atomic Energy Levels", NBS Circular 467, Vol. III, National Bureau of Standards: Washington, DC 1958 Note: all reprinted as NSRDS-NBS 35, National Bureau of Standards: Washington, DC 1971
Sansonetti 2005	J. E. Sansonetti and W. C. Martin, J. Phys. Chem. Ref. Data 34, 1559-2259 (2005) Handbook of Basic Atomic Spectroscopic Data Web: http://physics.nist.gov/PhysRefData/Handbook/
Johansson 1966	L. Johansson, Ark. Fys. 31, 201-235 (1966) Spectrum and Term System of the Neutral Carbon Atom
est unc	estimated uncertainty