After 3/11: The Evolution of Jihadist Networks in Spain / Terrorism Monitor, Volume 4, Issue 1 (January 12, 2006)

http://www.jamestown.org/terrorism/news/article.php?articleid=2369863
Javier Jordán, Robert Wesley"Nearly two years after the March 11, 2004 terrorist attacks in Madrid, new militant Islamist cells continue to be disrupted in Spain on a regular basis."
PDF - http://www.jamestown.org/terrorism/news/uploads/TM_004_001.pdf