Article
The astronomical journal  (2003)

The Chandra Deep Field North Survey. XV. Optically Bright, X-Ray-Faint Sources

Hornschemeier, A. E.; Bauer, F. E.; Alexander, D. M.; Brandt, W. N.; Sargent, W. L. W.; Bautz, M. W.; Conselice, C.; Garmire, G. P.; Schneider, D. P.; Wilson, G.