Gilsanz, Ramon; Edward M. DePaola; Christopher Marrion; Harold "Bud" Nelson (May 2002). "WTC7 (Chapter 5)". World Trade Center Building Performance Study(PDF). FEMA. Archived(PDF) from the original on March 5, 2008. Retrieved February 17, 2008.
Gilsanz, Ramon; Edward M. DePaola; Christopher Marrion; Harold "Bud" Nelson (May 2002). "WTC7 (Chapter 5)". World Trade Center Building Performance Study(PDF). FEMA. Archived(PDF) from the original on March 5, 2008. Retrieved February 17, 2008.