diff --git a/README.adoc b/README.adoc
index d11da69..fdac405 100644
--- a/README.adoc
+++ b/README.adoc
@@ -13105,6 +13105,8 @@ In POSIX 7 mmap always maps to a file.
 
 If we add the MAP_ANONYMOUS Linux extension however, this is not required, and mmap can be used to allocate memory like malloc.
 
+Answers: https://stackoverflow.com/questions/4779188/how-to-use-mmap-to-allocate-a-memory-in-heap
+
 ===== mmap file
 
 Memory mapped file example: link:userland/posix/mmap_file.c[]