1. Incidence and prediction of post dural puncture headache, a prospective study of 1021 spinal anaesthesia;lybecker;Anaesthesia analgesia,1990
2. Post dural puncture headache and spinal needle design;Halpern;Metanalysis Anaesthesiology,1994
3. 3. Ross BK, Chadwick HS, Mancuso JJ, et al. Sprolte needle for obstetric anaesthesia decreased incidence of post dural puncture headache. reg anaesthesia 1992;17(1):29-33.
4. 4. Tarkkila PJ, Heine H, tervo RR. Comparison of sprotte and quincke needle with respect to the Pdph and backache. Reg Anaesth 1992;17(5):283-7.
5. 5. Shnider SM, Levenson G. Anaesthesia for caesarian section In: Shinder SM, Levinson g editors anaesthesia for obstetricies. Baltimore: williams & wilkins: 1987;2nd edition:159-78.