Structural changes detection with use of operational spatial filter / Jeremi WÓJCICKI, Krzysztof MENDROK // W: SURVEILLANCE 7 : [7\textsuperscript{th} international conference on Acoustical and vibratory surveillance methods and diagnostic techniques] : Chartres, France, October 29–30, 2013 : book of abstracts / Institut Universitaire de Technologie de Chartres. — France : [s. n.], [2013]. — S. 65. — Bibliogr. s. 65