►American Society of Anesthesiologists (ASA)

►Anaesthetists of Great Britain & Ireland, Association of (AAGBI)

►British Medical Association (BMA)

►Department of Health

►General Medical Council (GMC)

►Gasnet

►International Anesthesia Research Society (IARS)

►Medical Defence Union (MDU)

►National Library of Medicine, US

►NHS

►NHS Direct

►Royal College of Anaesthetists (RCA)