HIERTON, Tor; JANSEN, Knud. In Memoriam: Sten Frtberg. Acta Orthopaedica, [S. l.], v. 48, n. 4, p. 431–432, 1977. DOI: 10.3109/17453677708992021. Disponível em: https://actaorthop.org/actao/article/view/29276. Acesso em: 22 may. 2026.