Add reference to the memory layout

pablogsal · pablogsal · commit d2db8ada9c84 · 2020-01-21T02:41:00.000Z
diff --git a/garbage_collector.rst b/garbage_collector.rst
@@ -398,7 +398,8 @@ addresses are always a multiple of 4, hence end in ``00``, leaving the last 2 bi
 available; while on a 64-bit architecture, a word is 64 bits word = 8 bytes, so
 word-aligned addresses end in ``000``, leaving the last 3 bits available.
 
-The CPython GC makes use of two fat pointers:
+The CPython GC makes use of two fat pointers that corresponds to the extra fields
+of ``PyGC_Head`` discussed in  `Memory layout and object structure`_:
 
   .. warning::
 
