1. Ayer, J. B. (1921) Spinal subarachnoid block as determined by combined cisternal and lumbar puncture: with special reference to the early diagnosis of cord tumour.Arch. Neurol. Psychiat. (Chic.) 4, 529–541.
2. Gilland, O. (1966)CSF dynamic diagnosis of spinal block. Almquist & Wiksell, Stockholm.
3. Lakke, J. P. W. F. (1969) Queckenstedt's test.Exerpta. Med. Amsterdam.
4. Lamb, H. (1898) On the velocity of sound in a tube, as affected by the elasticity of the walls.Manchester Memoirs xlii, 1–16.
5. Landau, L. D. andLifshitz, E. M. (1959) InFluid Mechanics, Course of theoretical physics 6. Pergamon Press.