diff --git a/existential-types.md b/existential-types.md
index b8a4048..076d703 100644
--- a/existential-types.md
+++ b/existential-types.md
@@ -2,6 +2,8 @@ https://gist.github.com/CMCDragonkai/b203769c588caddf8cb051529339635c
 
 http://iveselov.info/posts/2012-08-30-existential-types.html
 
+https://markkarpov.com/post/existential-quantification.html
+
 Great explanation by Anupam Jain in FPNCR Telegram channel :)
 
 Everything gets a forall.