Oxygen, sodium, magnesium, and aluminium as tracers of the galactic bulge formation A. Lecureur, V. Hill, M. Zoccali, B. Barbuy, A. Gómez, D. Minniti, S. Ortolani and A. Renzini A&A, 465 3 (2007) 799-814 Published online: 02 January 2007 DOI: 10.1051/0004-6361:20066036