Everything You Need to Know About Belly Buttons
Navel - Wikipedia
The umbilical cord: what is it and what does it do? - Netmums
Here's what your belly button can tell about your health
Which bacteria hang out in belly buttons? Here's a who's who
Why do we have a Belly Button? + more videos
5 Strange Facts About Belly Buttons
Here's what your belly button can tell about your health
What's behind the belly button?
Bellybutton challenge: This is damaging.
Guide to Kids' Belly Pain
Explainer: What is metabolic syndrome?
Do test tube babies have belly buttons? - Quora
Where Is Baby's Belly Button? by Karen Katz, Board Book
A father's tears for the pain of endometriosis, Letters