Add links to helpful external resources.
diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst
index 39aab16..b735c8f 100644
--- a/Doc/library/functions.rst
+++ b/Doc/library/functions.rst
@@ -973,6 +973,9 @@
*reverse* is a boolean value. If set to ``True``, then the list elements are
sorted as if each comparison were reversed.
+ To convert an old-style *cmp* function to a *key* function, see the
+ `CmpToKey recipe in the ASPN cookbook
+ <http://code.activestate.com/recipes/576653/>`_\.
.. function:: staticmethod(function)
diff --git a/Doc/library/math.rst b/Doc/library/math.rst
index 55e03bf..d59296a 100644
--- a/Doc/library/math.rst
+++ b/Doc/library/math.rst
@@ -93,6 +93,10 @@
occasionally double-round an intermediate sum causing it to be off in its
least significant bit.
+ For further discussion and two alternative approaches, see the `ASPN cookbook
+ recipes for accurate floating point summation
+ <http://code.activestate.com/recipes/393090/>`_\.
+
.. function:: isinf(x)