Long term variability of Cyg X-1 - II. The rms-flux relationT. Gleissner, J. Wilms, K. Pottschmidt, P. Uttley, M. A. Nowak and R. StaubertA&A, 414 3 (2004) 1091-1104DOI: https://doi.org/10.1051/0004-6361:20031684
