The stellar population of the Rosat North Ecliptic Pole survey G. Micela, L. Affer, F. Favata, J. P. Henry, I. Gioia, C. R. Mullis, J. Sanz Forcada and S. Sciortino A&A, 461 3 (2007) 977-982 Published online: 16 October 2006 DOI: 10.1051/0004-6361:20066146