TY - RPRT TI - Atomic energy levels - the rare-earth elements : the spectra of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetitum AU - Martin, W C AU - Zalubas, Romuald AU - Hagan, Lucy PY - 1978 PB - National Bureau of Standards CY - Gaithersburg, MD SN - NBS NSRDS 60 DO - 10.6028/NBS.NSRDS.60 ER -