Chemical analysis of very metal-poor turn-off stars from SDSS-DR12 P. François, E. Caffau, S. Wanajo, D. Aguado, M. Spite, M. Aoki, W. Aoki, P. Bonifacio, A. J. Gallagher, S. Salvadori and F. Spite A&A, 619 (2018) A10 Published online: 30 October 2018 DOI: 10.1051/0004-6361/201833824