Detailed spectroscopic analysis of the Trapezium cluster stars inside the Orion nebula - Rotational velocities, stellar parameters, and oxygen abundancesS. Simón-Díaz, A. Herrero, C. Esteban and F. NajarroA&A, 448 1 (2006) 351-366DOI: https://doi.org/10.1051/0004-6361:20053066