1. Department of Pediatrics, Ulm University, 89075 Ulm, Germany
2. Department of Health Management, Neu-Ulm University of Applied Sciences, 89231 Neu-Ulm, Germany
3. Health Sciences Library, Hospital Universitario La Paz, 28046 Madrid, Spain
4. Department of Neonatology, Department of Pediatrics, Hospital Universitario La Paz, Universidad Autonoma de Madrid, 28046 Madrid, Spain
5. Department of Mother and Child Health, Division of Neonatology, G. Salesi Children’s Hospital, 60123 Ancona, Italy
6. Department of Odontostomatologic and Specialized Clinical Sciences, Polytechnic University of Marche, 60020 Ancona, Italy
7. Department of General Pediatrics and Neonatology, Justus-Liebig-University, 35392 Giessen, Germany
8. Department of Neonatology, Leipzig University Hospital, 04103 Leipzig, Germany