This is a list of papers who's links had become broken and have had their links recently fixed. If you wanted a paper but could not download it, then you can check this list to see if it has become available once again.
If you would like to report that a paper fails to download, then I would kindly appreciate hearing of the page with the broken link (e.g., pp_models_64) plus (if you know it) a new source. Contact Me. Thanks.