content to forgo the traditional peer-reviewed journal process, stating: "If anybody is interested in my way of solving the problem, it's all there let them go and read about it". Despite this non-traditional method of publication, other mathematicians recognized this work by offering the Fields Medal and Clay Mathematics Millennium Prizes to Perelman, both of which he refused. While arXiv does contain some dubious e-prints, such as those claiming to refute famous theorems or proving famous conjectures such as Fermat's Last Theorem using only high-school mathematics, a 2002 article which appeared in Notices of the American Mathematical Society described those as "surprisingly rare". arXiv generally re-classifies these works, e.g. in "General mathematics", rather than deleting them; however, some authors have voiced concern over the lack of transparency in the arXiv screening process. Submission formats Papers can be submitted in any of several formats, including LaTeX, and PDF printed from a word processor other than TeX or LaTeX. The submission is rejected by the arXiv software if generating the final PDF file fails, if any image file is too large, or if the total size of the submission is too large. arXiv now allows one to store and modify an incomplete submission, and only finalize the submission when ready. The time stamp on the article is set when the submission is finalized. Access The standard access route is through the arXiv.org website or one of several mirrors. Other interfaces and access routes have also been created by other un-associated organisations. Metadata for arXiv is made available through OAI-PMH, the standard for open access repositories. Content is therefore indexed in all major consumers of such data, such as BASE, CORE and Unpaywall. As of 2020, the Unpaywall dump links over 500,000 arxiv URLs as the open access version of a work found in CrossRef data from the publishers, making arXiv a top 10 global host of green open access. Finally, researchers can select sub-fields and receive daily e-mailings or RSS feeds of all submissions in them. Copyright status of files Files on arXiv can have a number of different copyright statuses: Some are public domain, in which case they will have a statement saying so. Some are available under either the Creative Commons 4.0 Attribution-ShareAlike license or the Creative Commons 4.0 Attribution-Noncommercial-ShareAlike license. Some are copyright to the publisher, but the author has the right to distribute them and has given arXiv