WILLÉN, Helena. Tumor necrosis and prognosis in osteosarcoma. Acta Orthopaedica, [S. l.], v. 68, n. sup273, p. 126–129, 1997. DOI: 10.1080/17453674.1997.11744717. Disponível em: https://actaorthop.org/actao/article/view/20914. Acesso em: 19 may. 2026.