Bibliography

http://health.howstuffworks.com/human-body/systems/circulatory/blood1.htm

http://www.thenutritiondr.com/body-basics-red-blood-cells-hemoglobin-oxygen-carbon-dioxide/

http://www.hematology.org/Patients/Basics/

http://www.healthhype.com/red-blood-cells-functions-size-structure-life-cycle-pictures.html

http://www.psbc.org/hematology/02_how.htm