Influence of magnetic fields on the coherence effects in the Nai D1 and D2 lines J. O. Stenflo, A. Gandorfer, T. Wenzler and C. U. Keller A&A, 367 3 (2001) 1033-1048 Published online: 15 March 2001 DOI: 10.1051/0004-6361:20000495