[Air-pollution-proof valve for Entonox inhalation (author's transl)].
D000397:Air Pollution / Q000517:prevention & control*; D000769:Anesthesia, Inhalation / Q000295:instrumentation*; D009609:Nitrous Oxide; D009873:Operating Rooms; D010100:Oxygen
D009609:Nitrous Oxide; D010100:Oxygen