(F/E/S) : French, English and Spanish version; See French version in LES PROBLEMES JURIDIQUES DES VIDEO-CASSETTES ET DES DISQUES AUDIO-VISUELS; See Spanish version in LOS PROBLEMAS JURIDICOS DE LAS VIDEOCASETES Y DE LOS DISCOS AUDIOVISUALES; Study presented by Franca Klaver, Professor at the University of Amsterdam : at the request of UNESCO and WIPO : The author is an independent expert; the opinions expressed in it do not necessarily reflect those of UNESCO and/or WIPO;.