The invention is based in part on the discovery that nonselective \u03ba agonists that possess \u03bc receptor-mediated effects in addition to their \u03ba agonist effects can decrease cocaine self-administration more effectively and with fewer undesirable side effects than can highly selective \u03ba agonists. A search is performed, by a holographic correlator system, on a structured representation of original data, stored in a holographic data storage medium. The fold cooperates with one of the flanges for defining a pocket for receiving an edge of a sound panel.