Sound Velocity in Single Crystals of Synthetic Opals Bogomolov, V. N. ; Smirnov, I. A. ; Sharenkova, N. V. ; Bruls, G. Abstract Publication: Physics of the Solid State Pub Date: January 2001 DOI: 10.1134/1.1340208 Bibcode: 2001PhSS...43..194B