Update mathdata.md

courses/mathdata.md

@@ -29,6 +29,7 @@ Announcements will be posted on the [KWARC mathematical data mailing list](http:
 - *Time*: Friday, May 22, 2020 from 14:00 to 15:30 (Central European Summer Time, UTC+2)
 - *Location*: online at Zoom ID: 998 0468 1137
 - *Speaker*: Tom Wiesing (FAU)
+- [Slides](https://kwarc.info/people/twiesing/pubs/slides/2020_05_22_mdh.pdf)
 
 **Abstract.** MathDataHub provides dataset hosting and a searchable interface for the hosted dataset. 
 It was developed by Katja Berčič, Michael Kohlhase, Florian Rabe, and Tom Wiesing.