Moore, C.
(1971),
Atomic energy levels as derived from the analyses of optical spectra ::volume III. 42Mo to 57La, 72Hf to 89Ac, , National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.6028/NBS.NSRDS.35v3
(Accessed November 8, 2024)