The Gaia-ESO Survey: α-abundances of metal-poor stars R. Jackson-Jones, P. Jofré, K. Hawkins, A. Hourihane, G. Gilmore, G. Kordopatis, C. Worley, S. Randich, A. Vallenari, T. Bensby et al. (14 more) A&A, 571 (2014) L5 Published online: 13 November 2014 DOI: 10.1051/0004-6361/201425099