Non destructive testing of works of art by terahertz analysis Jean-Luc Bodnar, Jean-Jacques Metayer, Kamel Mouhoubi and Vincent Detalle Eur. Phys. J. Appl. Phys., 64 2 (2013) 21001 Published online: 15 November 2013 DOI: 10.1051/epjap/2013130132