References and Notes for Niobium ( Nb )

DHL86 D. W. Duquette, E. A. Den Hartog, and J. E. Lawler, J. Quant. Spectrosc. Radiat. Transfer 35, 281 (1986).
M00 D. C. Morton, Astrophys. J. Suppl. Ser. 130, 403 (2000).
M52 C. E. Moore, Atomic Energy Levels, Natl. Bur. Stand. (U.S.) Circ. 467, Vol. II (1952); reprinted as Natl. Stand. Ref. Data Ser., Natl. Bur. Stand. (U.S.) 35 (1971).
MCS75 W. F. Meggers, C. H. Corliss, and B. F. Scribner, Natl. Bur. Stand. (U.S.), Monogr. 145 (1975).
RCL00 A. N. Ryabtsev, S. S. Churilov, and U. Litzén, Phys. Scr. 62, 368 (2000).
RMBH87 D. M. Rayner, S. A. Mitchell, O. L. Bourne, and P. A. Hackett, J. Opt. Soc. Am. B 4, 900 (1987).