@Article GSJRA07,
author = "Giraud, Fr\'ed\'eric and Semail, Betty and Julien, ARAGONES and Robineau, Jacques and Audren, Jean-Thierry",
title = "Precise position control of a travelling wave ultrasonic motor",
journal = "IEEE Transactions on Industry Applications",
number = "4",
volume = "43",
pages = "934-971",
month = "jul",
year = "2007",
}