diff --git a/README.adoc b/README.adoc
index 644d17e..361c13b 100644
--- a/README.adoc
+++ b/README.adoc
@@ -144,4 +144,4 @@ Variables and functions can be added to a context both programmatically and ad a
 
 == Expressions syntax
 
-See #TODO link to doc/Expr.html#
+See https://cdn.paas.portale-stac.it/howto/go-pkg/expr/doc/Expr.html[Expr documentation] for a complete reference of the expression syntax and available functions.