Mendes, Fernando de Mello. <br/><br/>
use of modal analysis in the mechanical characterization of- rock masses / Fernando de Mello Mendes, L. Aires de Barros-, F. Peres Rodrigues. 

 - Lisboa, Portugal : Laboratorio Nacional de Engenharia Civil 
 - [7] p. 
 - Memoria; No.340 / Laboratorio Nacional de Engenharia Civil .