1. Ossified posterior longitudinal ligament: a clinicopathologic study;Ono;Spine,1977
2. Ossification of the posterior longitudinal ligament of the spine;Tsuyama;Clin Orthop Relat Res,1984
3. On an autopsied case of compression myelopathy with a callus formation in the cervical spinal canal;Tsukimoto;Nihon Geka Hokan,1960
4. On paraplegia depending on disease of the ligaments of the spine;Key;Guy Hosp Rep,1838
5. History of research;Nakamura,2006