Disk origin of the Milky Way bulge: the necessity of the thick disk P. Di Matteo, F. Fragkoudi, S. Khoperskov, B. Ciambur, M. Haywood, F. Combes and A. Gómez A&A, 628 (2019) A11 Published online: 26 July 2019 DOI: 10.1051/0004-6361/201832606