Deletion of European Summer School in Logic, Language and Information

Comment: I tried to find reliable sources but failed. I think one of the main problems is that – as the name suggests – ESSLLI is primarily a summer school (≈ somewhat similar to a bunch of university-level courses) and not a traditional academic conference (≈ researchers telling about their latest work). Therefore ESSLLI is not listed in conference rankings, conference impact factor lists, collections of bibliographies, etc. Sure, there are workshops in addition to the courses, but I think none of the workshops alone is particularly notable, and hence it isn't easy to find any reliable sources for them, either. I found several blog posts that seem to give the impression that ESSLLI could be notable, but naturally we should have something non- to satisfy 
Stance: comment
Cited policy: Wikipedia:Verifiability (WP:SPS||WP:V)