1. Department of Cardiothoracic Surgery, Friedrich-Schiller-University Jena , Germany
2. Department of Cardiothoracic Surgery at New York Presbyterian, Weill Cornell Medical Center , USA
3. Samuel J. Wood Library and C.V. Starr Biomedical Information Center, Weill Cornell Medicine , New York, NY, USA
4. Department of General Surgery, Maimonides Medical Center , Brooklyn, NY, USA
5. Nuffield Department of Surgical Sciences, University of Oxford , Oxford, UK