An XMM-Newton observation of the multiple system HD 167971 (O5-8V + O5-8V + (O8I)) and the young open cluster NGC 6604M. De Becker, G. Rauw, R. Blomme, J. M. Pittard, I. R. Stevens and M. C. RunacresA&A, 437 3 (2005) 1029-1046DOI: https://doi.org/10.1051/0004-6361:20052810