1Dimitrios, Emmanoulopoulos., 2007,Dissertation for the degree of Doctor, Ruperto - Carola University of Heidelberg.
2Dickey, J. M., Lockman, F. J. 1990, ARA&A, 28, 215.
3Nandra K., George I. M., et al. ASCA Observations of Seyfert 1 Galaxies. I. Data Analysis, Imaging, and Timing [ J]. ApJ. 1997, 476: 70.
4Vaughan S. , Edelson R acterizing the variability properties et al. On char- of X - ray light curves from active galaxies [ J ]. MNRAS. 2003 345:1271.