Benedetto Allotta Valentina Colla Gianluca Bioli A Mechatronic Device for Simulating Push-Buttons and Knobs. 636-642 1999 ICMCS, Vol. 1 http://computer.org/conferen/proceed/icmcs/0253/Volume%201/02539636abs.htm db/conf/icmcs/icmcs99-1.html#AllottaCB99