1[1]Westling F, Milson I, Zetterstrong A, et al. Effects of nitrous oxide/oxygen inhalation on the maternal circulation during vaginal delivery. Acta Anaesthesiol Scand, 1992, 3175-3181.
2[2]Lawes EG, newman B, Campbell MJ, et al. Maternal inspired oxygen concentration and neonatal status for caesarean section under general anaesthesia: comparison of effects of 33% or 50% oxygen in nitrous oxide. Br J Anaesth , 1998, 61(2):250-254.
