Radial abundance gradients in the outer Galactic disk as traced by main-sequence OB stars G. A. Bragança, S. Daflon, T. Lanz, K. Cunha, T. Bensby, P. J. McMillan, C. D. Garmany, J. W. Glaspey, M. Borges Fernandes, M. S. Oey and I. Hubeny A&A, 625 (2019) A120 Published online: 23 May 2019 DOI: 10.1051/0004-6361/201834554