T R, K S, K K. Posturograph with position-sensitive detector and method for it?s preparing [Internet]. BG Patent. 1999 . Report No.: 61749. http://worldwide.espacenet.com/publicationDetails/originalDocument?CC=BG&NR=61749B1&KC=B1&FT=D&date=19980529&DB=EPODOC&locale=en_EP