1. Central Venous Catheters- ultrasound locating devices (No 49), NHS National Institute for Health and Clinical Excellence, 2002 October 17th
2. Ultrasound guidance in regional anaesthesia;Marhofer;Br J Anaesth,2005
3. Ultrasound visibility of needles used for regional nerve block: an in vitro study;Scafhalter-Zoppoth;Reg Anesth Pain Med,2004
4. Visualisation of needle position using ultrasonography;Chapman;Anaesthesia,2006
5. Brachial plexus examination and electrical stimulation: a volunteer study;Perlas;Anesthesiology,2003