In the course of the investigation, Committee staff reviewed more than 30,000 pages of documentation provided by the intelligence community. The Committee requested that it be supplied copies of the President's Daily Briefs (PDBs) concerning Iraq's WMD capabilities and ties to terrorism, but the White House denied that request. An article by journalist Murray Waas has described a specific controversy over the PDB for September 21, 2001, which allegedly said that the US intelligence community had "no evidence" linking Saddam Hussein to the September 11 attacks, and "scant credible evidence" that Iraq had any significant collaborative ties with al Qaeda.[3]