The long-term millimeter activity of active galactic nuclei S. Trippe, M. Krips, V. Piétu, R. Neri, J. M. Winters, F. Gueth, M. Bremer, P. Salome, R. Moreno, J. Boissier and F. Fontani A&A, 533 (2011) A97 Published online: 07 September 2011 DOI: 10.1051/0004-6361/201015558