"
Have you read this page on the use of arxiv which basically says it can be alright to use it as a source? Apart from that the 2 papers mentioned in the 'In-line notes and references' section have been published in peer-reviewed journals (but link to the arxiv version) and of the 5 arxiv links in the 'Further reading' 2 have also been published in journals, 1 also in a conference proceedings and 1 also as a book of lecture notes. This looks like potentially quite good sourcing to me. Whether the content of the article matches the information contained in the sources is another matter. ₰ "