Fix markup.
diff --git a/Doc/library/collections.rst b/Doc/library/collections.rst
index 587d634..21b0924 100644
--- a/Doc/library/collections.rst
+++ b/Doc/library/collections.rst
@@ -60,9 +60,9 @@
Lookups search the underlying mappings successively until a key is found. In
contrast, writes, updates, and deletions only operate on the first mapping.
- A class:`ChainMap` incorporates the underlying mappings by reference. So, if
+ A :class:`ChainMap` incorporates the underlying mappings by reference. So, if
one of the underlying mappings gets updated, those changes will be reflected
- in class:`ChainMap`.
+ in :class:`ChainMap`.
All of the usual dictionary methods are supported. In addition, there is a
*maps* attribute, a method for creating new subcontexts, and a property for