Quite right, it is fan-fiction as long as you can't find an additional source, which in this case is very unlikely.
For the part of Men I found a more reliable source:
Lalaith's Middle-Earth Science Page
I linked the main page, but it is in english so you will find your way. The site features also some other very nice articles. So I thought it is beter give you the chance to see it completly.
Respectfully
Findegil