Ackermann, M., Ajello, M., Allafort, A., Baldini, L., Ballet, J., Barbiellini, G., et al. (2012). Search for gamma-ray emission from X-ray-selected Seyfert galaxies with Fermi-LAT. The Astrophysical Journal, 747(2): 104, pp. 1-17. doi:10.1088/0004-637X/747/2/104.