1[1]MacNab I,Negative disc exploration an analysis of the causes of nerve- root involvement in sixty- eight patients.J Bone Joint Surg(Am),1971; 53:891.
2[2]Dilke TF,Burry HC,Grahame R.Extradural corticosteroid injection in management of lumbar nerve root compression.BMJ 1973;2:635.
3[3]Pfirrmann CA,Oberholzer PA,Zanetti,et al. Selective nerve root blocks for the treatment of sciatica evaluation of injection site and effective- ness- A study with patient and cadavers.Radiology 2001;221:704.
4[4]Cassidy JD,Carroll LJ,Cote P.The Saskatchewan health and back pain survey:the prevalence of low back pain and related disability in Saskatchewan adults.Spine 1998;23:1860.