Људско тело — разлика између измена

* {{Cite book |ref= harv|last=Burton|first=George|title=Chemical Storylines|url=https://books.google.com/books?id=zvbV4M0-YdEC|year=2000|edition=2|publisher=Heinemann|isbn=978-0-435-63119-2}}

* {{Cite book |ref= harv|last=Roza|first=Greg|title=Inside the Human Body: Using Scientific and Exponential Notation|url=https://books.google.com/books?id=vhO8Ia2ik7oC|year=2006|publisher=The Rosen Publishing Group|isbn=978-1-4042-3362-1|pages=21}}