Factors Affecting the Learning Curve in the Endoscopic Ultrasound-Guided Sampling of Solid Pancreatic Lesions: A Prospective Study oleh Marcel Razpotnik, Simona Bota, Mathilde Kutilek, Gerolf Essler, Christian Urak, Julian Prosenz, Jutta Weber-Eibel, Andreas Maieron, Markus Peck-Radosavljevic