diff --git a/07-Considering_Threadability.md b/07-Considering_Threadability.md
index c0d3a7e..e5e19b8 100644
--- a/07-Considering_Threadability.md
+++ b/07-Considering_Threadability.md
@@ -15,4 +15,6 @@ For member variables it is good practice to use mutex and mutable together. This
 * A mutable member variable is presumed to be a shared variable so it should be synchronized with a mutex (or made atomic)
 * If a member variable is itself a mutex, it should be mutable. This is required to use it inside a const member function.
 
-For more information see the following article from Herb Sutter: http://herbsutter.com/2013/05/24/gotw-6a-const-correctness-part-1-3/
\ No newline at end of file
+For more information see the following article from Herb Sutter: http://herbsutter.com/2013/05/24/gotw-6a-const-correctness-part-1-3/
+
+See also [related safety discussion](04-Considering_Safety.md#consider-return-by-value-for-mutable-data-const--for-immutable) about `const &` return values