Feasibility of an Updated Randomised Controlled Trial on Surgical Urolithiasis Treatments: The Pilot Trial for the German Endoscopic versus Shock Wave Therapy Study (GESS). - Schoenthaler M; Hein S; Wilhelm K; Pohlmann PF; Praus F; Walther T; Schmoor C; Gratzke C; Miernik A (European urology focus, 2022)