Demand analgesia and anesthesia in obstetrics: an evaluation of apparatus and technic.
D000403:Airway Resistance; D000698:Analgesia / Q000295:instrumentation*; D000773:Anesthesia, Obstetrical / Q000295:instrumentation*; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D008722:Methods; D009609:Nitrous Oxide / Q000008:administration & dosage; D010102:Oxygen Inhalation Therapy; D011247:Pregnancy
D009609:Nitrous Oxide