You tried going to https://www.arts.ubc.ca/sheryl-lightfoot-on-the-un-declaration-on-the-rights-of-indigenous-peoples/, and it doesn't exist. All is not lost! You can search for what you're looking for.
https://www.arts.ubc.ca/sheryl-lightfoot-on-the-un-declaration-on-the-rights-of-indigenous-peoples/