1. Atomic energy levels i;Moore;Natl Bur Stand (US) Circ No,1971
2. Spectrum and the energy levels of neutral argon;Minnhagen;Ar I, J Opt Soc Am,1973
3. Wavelengths and energy levels of ar i and ar II based on new interferometric measurements in the region 3400-9800 Å;Norlen;Phys Scr,1973
4. New interferometric observations of ar i in the photographic region;Li;J Opt Soc Am,1974
5. Kramida A, Ralchenko Y, Reader J. NIST ASD Team. NIST atomic spectra database (ver. 5.5.6). 2018. [Online]. Available: https://physics.nist.gov/asd [2018, August 30]. National Institute of Standards and Technology, Gaithersburg, MD.