TY  - RPRT
TI  - Interobserver variability in grading Perthes' disease.
AU  - E D Simmons
AU  - H K Graham
AU  - J P Szalai
PY  - 1990
DO  - 10.1302/0301-620x.72b2.2312555
UR  - https://pubmed.ncbi.nlm.nih.gov/2312555/
ID  - 2312555
ER  -