TY  - JOUR
AU  - Hardcastle, PH
AU  - Ross, R
AU  - Hamalainen, M
AU  - Mata, A
DO  - doi:10.1302/0301-620X.62B4.7430217
UR  - https://doi.org/10.1302/0301-620X.62B4.7430217
TI  - Catterall grouping of Perthes' disease. An assessment of observer error and prognosis using the Catterall classification
T2  - The Journal of Bone & Joint Surgery British Volume
VL  - 62-B
IS  - 4
PY  - 1980
SP  - 428
EP  - 431
ER  -