[jkp56]

Legit links need quite a bit of research, like reading a 700 pages book only to realise that it consists on references to older more authoritative and much bigger books written a couple centuries earlier. These "sources" look like a tree with a few "root" ones written or said supposedly by a buddha. The closer the book or it's author to the root, the more legit it is. Technically, you can start from any author in this tree and discover the rest via references. One of the most cited authors is Atisa, who lived about 1000 years ago.