Line shapes of the magnesium resonance lines in cool DZ white dwarf atmospheresN. F. Allard, J. F. Kielkopf, S. Blouin, P. Dufour, F. X. Gadéa, T. Leininger and G. GuillonA&A, 619 (2018) A152DOI: https://doi.org/10.1051/0004-6361/201834067