C/O vs. Mg/Si ratios in solar type stars: The HARPS sample L. Suárez-Andrés, G. Israelian, J. I. González Hernández, V. Zh. Adibekyan, E. Delgado Mena, N. C. Santos and S. G. Sousa A&A, 614 (2018) A84 Published online: 19 June 2018 DOI: 10.1051/0004-6361/201730743