International Perthes Study Group Members. Interobserver and intraobserver reliability of the modified Waldenström classification system for staging of Legg–Calvé–Perthes disease.

Hyman JE, Trupia EP, Wright ML, Matsumoto H, Jo CH, Mulpuri K, Joseph B, Kim HKW, International Perthes Study Group Members. Interobserver and intraobserver reliability of the modified Waldenström classification system for staging of Legg–Calvé–Perthes disease. J Bone Joint Surg Am. April 2015. DOI:10.2106/JBJS.N.00887.