1. Glosten B. Anesthesia for obstetrics and anesthesia. 5th ed. New York:Churchill Livingston,
2000:2037-42.
2. Wall PD. and Melzak R.Texbook of pain.2nd ed. Edinburgh:Churchill Livingstone,1989.
3. Bonica JJ. The Management of pain.2nd ed. Philadelphia:Lea & Febiger,1990 .
4.Naghibee K, Alameh Z, Montazeree K.Which of these are better? No pain labor or cesarean
section? 1st ed. Esfehan university publication,2001: 201-30.
5. Abram SE, Haddox JD.Pain clinic manual.2nd ed. Philadelphia:Lippincott Williams & Wilkins,
2000.:109-17
6. Cunningham FG, Leveno KJ, Bloom SL, Hauth JC, Gilstrap III L, Wenstrom KD.Williams
obstetrics.22nd ed.New York:McGraw-Hill,2005..
7. Miller RD.Anesthesia.5th ed. Philadelphia:Churchill Livingstone,2000:1520-48 ,2024-68.
8. Crafter H. Pain-free labour. Nurs Times 1989;20:66-88.
9. Eger IIE. Nitrous oxide in obstetrics. New York:Elsevier,1985:185-200.
10. Ji X, Qi H, Liu A.Clinical study on labor pain relife using the combined spinal-epidural analgesia and
inhaling nitrous oxid.Zhonghua Fu Chan Ke Za Zhi 2002 Jul;37(7):398-401
11. Carstoniu JLS, Norman P, Daley DK,Sandler AN.Nitrous oxide in early labor. Safety and analgesic
efficacy assessed by a double-blind, Placebo-controlled study.Anesthesiology 1994 Jan;80(1):30-5.
12. Soyannwo OA. Self-administered Entonox in labor: report of the experience in Ibadan.Afr J Med Sci
1985 Mar-Jun;14(1-2):95-8.
13. Wang B, Zhang X, Wei L.Application of nitrous oxide in labor analgesia.Zhonghua Fu Chan Ke Za
Zhi. 1994 Jun;29(6):330-1,380-1.
14. aram S, Atari M. Comparison of labor pain with or without inhalation entonox. J Esfehan Unive Med
Sci. 1998 Winter;16(53).
15. Bergeret S, Loffredo P, Bosson JL. Prospective national survey on alternatives to obstetrical peridural
analgesia.Ann Fr Anesth Reanim.2000 Aug;19(7):530-9.
16. Abboud T, Shniders S, Wright R. En flurane analgesia in obstetrics.Anesth Analg 1981;60: 133-7.
17. Stefani S,Hughe S, Shnider S.Neonatal neurobehavioral effects of inhalation analgesia for vaginal
delivery.Anesthesiology 1982;56:351-5.
18. Creasy RK, Resnik R. Maternal-fetal medicine : principles and practice.3rd ed. Philadelphia :
Saunders, 1994
19. Augustine AE.Induction of labor at tetm in primigravid wirt low bishops score: a comparsion of
three methods European.J Obstet Gynecol Reprod Biol 1995 Sep;58:119-125.
20. Leong EW, Sivanesaratnam V, Oh LL, Chan YK. Epidural analgesia in primigravidae in spontaneous
labor at term: a prospective study.J Obstet Gynecol Res.2000;26(4):271-5
21. Lawler K. Entonox: too useful to be limited to childbirth?.Prof Care Mother Child 1995; 5(1):19-21.
22. Mark A.Rosen.Nitrous oxid for relife of labor pain: a systematic review.Am J Obstet Gynecol
2002;186: S110-26.