HIGHLY EXCITED VIBRATIONAL STATES OF CYCLIC MOLECULES INVESTIGATED BY I.C.L.A SPECTROSCOPY WITH PHOTOACOUSTIC DETECTION L. LESPADE, S. RODIN, D. CAVAGNAT et S. ABBATE J. Phys. IV France, 01 C7 (1991) C7-517-C7-520 DOI: 10.1051/jp4:19917136