Touloupakis G, Stuflesser W, Ferrara F, Maione A, Antonini G, Crippa C. Early-stage radiological critical analysis of unsuccessful cases following a four-part fracture osteosynthesis of the proximal humerus: focus on the “P” sign. Acta Biomed [Internet]. 2017 Aug. 23 [cited 2025 Mar. 12];88(2):178-84. Available from: https://mattioli1885journals.com/index.php/actabiomedica/article/view/5295