1. Department of Paediatric Surgery, Emma Children's Hospital, Amsterdam University Medical Center, University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
2. Tytgat Institute for Liver and Intestinal Research, Amsterdam University Medical Center, University of Amsterdam, the Netherlands
3. Department of General, Visceral, Thoracic and Vascular Surgery, University Hospital Bonn, Bonn, Germany
4. Medical Library, Vrije Universiteit, Amsterdam, the Netherlands