1. University Hospital Zürich; Department of Neonatology; Zürich Switzerland
2. University of Zürich; Zürich Switzerland
3. University Children's Hospital Tübingen; Department of Neonatology; Calwerstr. 7 Tübingen Baden-Wuerttemberg Germany 72076
4. Medical Center - Univ. of Freiburg, Faculty of Medicine, Univ. of Freiburg; Cochrane Germany; Breisacher Straße 153 Freiburg Germany 79110