1. D.J. Ewins, Modal Testing: Theory and Practice, Research studies press Letchworth, 1984.
2. Ultra-long blades for next generation offshore wind turbines;Korsgaard,2018
3. Modal Analysis Theory and Testing;Heylen,1998
4. Support Conditions for Free Boundary-Condition Modal Testing;Carne,2006
5. Introduction to Operational Modal Analysis;Brincker,2015