1. Benoit A., et al., 2003, A&A, 399, L19
2. Burigana C., De Zotti G., Danese L., 1995, A&A, 303, 323
3. Burigana C., De Zotti G., Feretti L., 2004, New Astron. Rev., 48, 1107
4. Burigana C., Finelli, F., Salvaterra R., Popa L.A., Mandolesi N., 2004, Recent Res. Devel. Astron. Astrophys., 2, 59, Research Signpost
5. Burigana C., La Porta L., Reich W., Reich P., Gonzalez-Nuevo J., Massardi M., De Zotti G., 2006a, in Proc. of “CMB and Physics of the Early Universe”, 20–22 April, 2006, Ischia, Italy, Editorial board: G. De Zotti et al., PoS(CMB2006)016 ( http://pos.sissa.it//archive/conferences/027/016/CMB2006_016.pdf ), astro-ph/0607469