diff --git a/Doc/library/ast.rst b/Doc/library/ast.rst
index 5373acd57b0..8c3b7e4ce4e 100644
--- a/Doc/library/ast.rst
+++ b/Doc/library/ast.rst
@@ -249,3 +249,8 @@ and classes for traversing abstract syntax trees:
    wanted *annotate_fields* must be set to ``False``.  Attributes such as line
    numbers and column offsets are not dumped by default.  If this is wanted,
    *include_attributes* can be set to ``True``.
+
+.. seealso::
+
+    `Green Tree Snakes <https://greentreesnakes.readthedocs.org/>`_, an external documentation resource, has good
+    details on working with Python ASTs.