RT Journal Article SR Electronic T1 Recurrent pyelonephritis as a sign of ‘sponge kidney’ JF Cleveland Clinic Journal of Medicine JO Cleve Clin J Med FD Cleveland Clinic SP 479 OP 480 DO 10.3949/ccjm.76a.08110 VO 76 IS 8 A1 Hung-Yi Chu A1 Ming-Tso Yan A1 Shih-Hua Lin YR 2009 UL http://www.ccjm.org/content/76/8/479.abstract AB