5Kourambas J, Delvecchio F C, Preminger G M, et al. Low power holmium laser for the management of urinary tract calculi, structures, and tumors[J]. J Enclourol, 2001,15:529-532.
6Zorcher T, Hochberger J, Schrott K M, et al. In vitro study concerning the efficiency of the frequency-doubled double-pulse Neodymium: YAG laser (FREDDY) for lithotripsy of calculi in the urinary tract [J]. Lasers Surg Med, 1999,25(1) :38-42.
7Brandt H, Rathert P. Endoscopic urinary stone lithotripsy with the U - 100 laser[FREDDY Technology] first clinical trials on 104 patients. 48th annual meeting of urology in north[J]. Rhine Westphalia Germany-Cologne, 2002,18-20.