Addisson Salazar Luis Vergara Jorge Igual Jorge Gosálbez Ramón Miralles ICA Model Applied to Multichannel Non-destructive Evaluation by Impact-Echo. 470-477 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3195&spage=470 2004 conf/ica/2004 ICA db/conf/ica/ica2004.html#SalazarVIGM04