Colgate, J.E.; Schenkel, G. (1994). "Passivity of a class of sampled-data systems: Application to haptic interfaces". Proceedings of 1994 American Control Conference - ACC '94. Vol. 3. pp. 3236–3240. doi:10.1109/ACC.1994.735172. ISBN0-7803-1783-1. S2CID7860568.
Colgate, J.E.; Schenkel, G. (1994). "Passivity of a class of sampled-data systems: Application to haptic interfaces". Proceedings of 1994 American Control Conference - ACC '94. Vol. 3. pp. 3236–3240. doi:10.1109/ACC.1994.735172. ISBN0-7803-1783-1. S2CID7860568.