1. Goldie I (1958) Granulation tissue in the ruptured intervertebral disc. Acta Pathol Scand 42:300–304
2. Hanson HJ (1952) A pathologic-anatomical study on disc degeneration in dogs. Acta Orthop Scand Suppl 11:1–117
3. Hirsch C (1959) Studies on the pathology of low back pain. J Bone Joint Surg 41B:237–243
4. Hoyland JA, Freemont AJ, Jayson MIV (1989) Intervertebral foramen venous obstruction. A cause of periradicular fibrosis. Apine 14:558–568
5. Hoyland JA, Freemont AJ (1991) The incidence and significance of psammoma bodies within nerve roots of lumbar spines. Neuro-Orthopaedics 11:83–89