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NIST NCSTAR 1 (2005), p. 8. Sivaraj Shyam-Sunder; Richard G. Gann; William L. Grosshandler; Hai S. Lew; Richard W. Bukowski; Fahim Sadek; Frank W. Gayle; John L. Gross; Therese P. McAllister; Jason D. Averill; James R. Lawson; Harold E. Nelson; Stephen A. Cauffman (September 2005). Final Report of the National Construction Safety Team on the Collapses of the World Trade Center Tower (NIST NCSTAR 1)(PDF) (Report). Federal Building and Fire Safety Investigation of the World Trade Center Disaster. National Institute of Standards and Technology (NIST).
NIST NCSTAR 1 (2005), p. 10. Sivaraj Shyam-Sunder; Richard G. Gann; William L. Grosshandler; Hai S. Lew; Richard W. Bukowski; Fahim Sadek; Frank W. Gayle; John L. Gross; Therese P. McAllister; Jason D. Averill; James R. Lawson; Harold E. Nelson; Stephen A. Cauffman (September 2005). Final Report of the National Construction Safety Team on the Collapses of the World Trade Center Tower (NIST NCSTAR 1)(PDF) (Report). Federal Building and Fire Safety Investigation of the World Trade Center Disaster. National Institute of Standards and Technology (NIST).
Building and Fire Research Laboratory (September 2005). Visual Evidence, Damage Estimates, and Timeline Analysis(PDF). National Institute of Standards and Technology (Report). United States Department of Commerce. p. 27. Archived(PDF) from the original on September 11, 2021. Retrieved August 24, 2021.
Building and Fire Research Laboratory (September 2005). Visual Evidence, Damage Estimates, and Timeline Analysis(PDF). National Institute of Standards and Technology (Report). United States Department of Commerce. p. 27. Archived(PDF) from the original on September 11, 2021. Retrieved August 24, 2021.