Hey Sue,
Welcome!
You have added the sources as text in the source section. Just above that line ==Sources== you have a single <ref> tag.
That code tells the system that anything after it, and before the closing tag </ref>, is 1 reference.
So in this case, the page does not show references as there is only one that is not ending.
Solution: delete the stray <ref> code and save (I tested, it works in preview, but will leave the honor to you.)