Clustering environment of BL Lacertae object RGB 1745+398 H. Lietzen, K. Nilsson, L. O. Takalo, P. Heinämäki, P. Nurmi, P. Keinänen and S. Wagner A&A, 482 3 (2008) 771-775 Published online: 04 March 2008 DOI: 10.1051/0004-6361:20078056