TY - RPRT TI - Atomic energy levels as derived from the analyses of optical spectra : volume III. 42Mo to 57La, 72Hf to 89Ac AU - Moore, Charlotte E PY - 1971 PB - National Bureau of Standards CY - Gaithersburg, MD SN - NBS NSRDS 35v3 DO - 10.6028/NBS.NSRDS.35v3 ER -