Walpoth, NB, K Habermacher, S Watson, and C Schönenberger. “Device-Less Patent Foramen Ovale Closure by Radiofrequency Thermal Energy”. Swiss Medical Weekly 138, no. 0708 (February 23, 2008): 108–108. Accessed April 15, 2024. https://smw.ch/index.php/smw/article/view/824.