1. Department of Endocrinology, Medical University of Varna, Clinic of Endocrinology, UMHAT “Sveta Marina”, Varna, Bulgaria
2. Division of Endocrinology, Department of Medicine, Leiden University Medical Center, Leiden, the Netherlands
3. Università “Federico II” di Napoli, Dipartimento di Medicina Clinica e Chirurgia, Sezione di Endocrinologia, Naples, Italy
4. Department of Pediatrics, Medical University of Varna, First Pediatric Clinic with Intensive Care, UMHAT “Sveta Marina”, Varna, Bulgaria
5. Department of Endocrinology and Metabolism, Amsterdam Gastroenterology Endocrinology & Metabolism, Amsterdam University Medical Centre, University of Amsterdam, Amsterdam, Netherlands
6. Adult Chair of MTG Pituitary of Endo-ERN