Zhu, M., Maher, M. A., Gu, W., Hunt, K. J., Myerson, M. S., & Li, S. (2023). Content validation of the progressive collapsing foot deformity classification. Journal of the Foot & Ankle, 17(3), 156–162. https://doi.org/10.30795/jfootankle.2023.v17.1731