1. Related articles, [Survey on practice of regional anaesthesia in Germany, Austria, and Switzerland. Part 1. Quality assurance and training concepts];Bartusseck;Anaesthesist,2004
2. Related articles, [Survey on current practice of regional anaesthesia in Germany, Austria, and Switzerland. Part 2. Use, success rates and techniques];Grau;Anaesthesist,2004
3. Related articles, links [Survey on practice of regional anaesthesia in Germany, Austria, and Switzerland. Part 3. Methods in obstetric anaesthesia];Bartusseck;Anaesthesist,2004
4. Ultrasonic localization of the lumbar epidural space;Cork;Anesthesiology,1980
5. Measurement of the depth of the epidural space using ultrasound;Currie;Br J Anaesth,1984