Detection of an X-ray periodicity in the Narrow-line Seyfert 1 Galaxy Mrk 766 with XMM-NewtonTh. Boller, R. Keil, J. Trümper, P. T. O'Brien, J. Reeves and M. PageA&A, 365 1 (2001) L146-L151DOI: https://doi.org/10.1051/0004-6361:20000083
