R.  Rizzo, ?A Permanent-Magnet Exciter for Magneto-Rheological Fluid-Based Haptic Interfaces?, IEEE Transactions on Magnetics, vol. 49, pp. 1390?1401, 2013. 

R.  Rizzo, Musolino, A., Scilingo, E. P., Bicchi, A., and Raugi, M., ?A Permanent Magnets Exciter for MRFs-based Haptic Interfaces?, in IEEE Conference on Electromagnetic Field Computation, Atene, 2008.