And as the late Rabbi Me'ir Kahana' (zt"l; Hy"d) pointed out, it is precisely those three sites whose Jewish ownership is most denied and disputed by the world at large.
But if you believe in the Bible at all, G-d makes so many references to the ownership of the land in Genesis alone that there is no need to research the deed.
Unfortunately, most people today do not believe in the Bible. Even "pro-Israel" liberal Jews (who are allergic to everything chr*stians believe, even their own Bible) base their belief in Israel's legitimacy on the Holocaust and "democracy."
My bad; it was Joseph’s Tomb, not Jacob’s.