Add some internal links.
diff --git a/Doc/glossary.rst b/Doc/glossary.rst
index 161e52c..54537d2 100644
--- a/Doc/glossary.rst
+++ b/Doc/glossary.rst
@@ -27,7 +27,7 @@
:ref:`2to3-reference`.
abstract base class
- Abstract Base Classes (abbreviated ABCs) complement :term:`duck-typing` by
+ :ref:`abstract-base-classes` complement :term:`duck-typing` by
providing a way to define interfaces when other techniques like
:func:`hasattr` would be clumsy. Python comes with many built-in ABCs for
data structures (in the :mod:`collections` module), numbers (in the
diff --git a/Doc/library/collections.rst b/Doc/library/collections.rst
index d5ad482..d78e7c9 100644
--- a/Doc/library/collections.rst
+++ b/Doc/library/collections.rst
@@ -27,10 +27,9 @@
:class:`defaultdict` dict subclass that calls a factory function to supply missing values .. versionadded:: 2.5
===================== ==================================================================== ===========================
-In addition to containers, the collections module provides some ABCs
-(abstract base classes) that can be used to test whether a class
-provides a particular interface, for example, whether it is hashable or
-a mapping.
+In addition to the concrete container classes, the collections module provides
+:ref:`abstract-base-classes` that can be used to test whether a class provides a
+particular interface, for example, whether it is hashable or a mapping.
.. seealso::