References

American Thoracic Society. Why do I need oxygen therapy? http://www.thoracic.org/clinical/copd guidelines/for patients/why do i need oxygen therapy.php. Accessed on May 8, 2014. National Home Oxygen Patients Association. Understanding oxygen therapy: a patient guide to long term supplemental oxygen. http://www.homeoxygen.org/assets/docs/Understanding%20Oxygen%20Therapy%202013.pdf. Accessed on May 8, 2014.