KNUTSEN, Olav; YGGE, Hans. Prolonged Extradural Anaesthesia with Bupivacaine at Lumbago and Sciatica. Acta Orthopaedica, [S. l.], v. 42, n. 4, p. 338–352, 1971. DOI: 10.3109/17453677108989054. Disponível em: https://actaorthop.org/actao/article/view/29886. Acesso em: 7 may. 2026.