More information, from the 9/16 LATimes (I do apologize for posting from these sources, but they seem to be the ones covering the story).
http://www.latimes.com/news/nationworld/nation/la-na-reporter16sep16,1,2765522.story?coll=la-headlines-nation
[Excerpted]
"Cooper's first deposition was limited to conversations he had last year with I. Lewis 'Scooter' Libby, chief of staff to Vice President Dick Cheney."
[Excerpted]
"People familiar with the case said that Fitzgerald now wants to investigate other sources used by Cooper but that the prosecutor has not specified whom."
Hmmmmmmmmmm