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- [22] RAPID X-RAY VARIABILITY FROM THE SEYFERT 1 GALAXY NGC4051 ASTROPHYSICAL JOURNAL, 1983, 269 (02): : L31 - L35
- [26] Ubiquitous variability of X-ray absorbing column densities in Seyfert 2 galaxies ASTROPHYSICAL JOURNAL, 2002, 571 (01): : 234 - 246