diff --git a/events/GI2020/index.md b/events/GI2020/index.md
index a3414267959333181379e58a04514d65dd47c3ff..a606b47791a37d50084104599931db5d6e99e9f1 100644
--- a/events/GI2020/index.md
+++ b/events/GI2020/index.md
@@ -20,10 +20,10 @@ All participants must **register** [here](https://docs.google.com/forms/d/1hF5Tg
 
 #### Session 1: 10:00 - 12:15 (chair: Sergey Goncharov)
 
-* 10:00: Ana Sokolova, **Invited talk**: Algebraic Traces for Probability and Nondeterminism [slides](solokova.pdf)
-* 10:45: David Fuenmayor,	Paraconsistent and paracomplete logics in Isabelle/HOL [slides](fuenmayor.pdf)
-* 11:05: Florian Bruse and Martin Lange and Marco Sälzer, On Finite Convergence of Fixpoints in the Modal Mu-Calculus [slides](saelzer.pdf)
-* 11:25: Ali Farjami, Normative Reasoning: A Computational Challenge [slides](farjami.pdf)
+* 10:00: Ana Sokolova, **Invited talk**: Algebraic Traces for Probability and Nondeterminism [slides (if any)](solokova.pdf)
+* 10:45: David Fuenmayor,	Paraconsistent and paracomplete logics in Isabelle/HOL [slides (if any)](fuenmayor.pdf)
+* 11:05: Florian Bruse and Martin Lange and Marco Sälzer, On Finite Convergence of Fixpoints in the Modal Mu-Calculus [slides (if any)](saelzer.pdf)
+* 11:25: Ali Farjami, Normative Reasoning: A Computational Challenge [slides (if any)](farjami.pdf)
 * 11:45: *break with free discussion in gather.town*
 
 #### Session 2: 13:00 - 15:15 (chair: Claudia Schon)