High lateral resolution spectroscopic imaging of surfaces: The undulator beamline “nanospectroscopy” at Elettra A. Locatelli, A. Bianco, D. Cocco, S. Cherifi, S. Heun, M. Marsi, M. Pasqualetto and E. Bauer J. Phys. IV France, 104 (2003) 99-102 DOI: 10.1051/jp4:200300038