Blank field sources in the ROSAT HRI Brera multiscale wavelet catalogM. Chieregato, S. Campana, A. Treves, A. Moretti, R. P. Mignani and G. TagliaferriA&A, 444 1 (2005) 69-77DOI: https://doi.org/10.1051/0004-6361:20041726