E. P.  Scilingo, Bicchi, A., De Rossi, D., and Iacconi, P., ?Haptic display able to replicate the rheological behaviour of surgical tissues?, in Proc. 20th International Conference IEEE/EMBS, Hong Kong, 1998, pp. 1738-1741. 

A.  Bicchi, Canepa, G., De Rossi, D., Iacconi, P., and Scilingo, E. P., ? A sensor-based minimally invasive surgery tool for detecting tissue elastic properties ?, in Proc. IEEE Int. Conf. on Robotics and Automation, 1996, pp. 884-888.