U. S. Dept. Defense . Shock and Vibration Information Center.The shock and vibration bulletin．47, pt.4：Structural dynamics, systems identification, computer applications.Office of the Director of Defense Research and Engineering,1977.
Shock and Vibration Information Center, of Defense, U. S..The shock and vibration bulletin．V. 47.4，Structural dynamics, systems identification, computer applications.,1977.
