Hyperfine structure measurements of neutral niobium with Fourier transform spectroscopy S. Kröger, A. Er, I. K. Öztürk, G. Başar, A. Jarmola, R. Ferber, M. Tamanis and L. Začs A&A, 516 (2010) A70 Published online: 01 July 2010 DOI: 10.1051/0004-6361/200913922