Issue #18758: Fixed and improved cross-references.
diff --git a/Doc/library/math.rst b/Doc/library/math.rst
index 7c6f0b4..562388e 100644
--- a/Doc/library/math.rst
+++ b/Doc/library/math.rst
@@ -136,8 +136,9 @@
.. function:: trunc(x)
- Return the :class:`Real` value *x* truncated to an :class:`Integral` (usually
- a long integer). Uses the ``__trunc__`` method.
+ Return the :class:`~numbers.Real` value *x* truncated to an
+ :class:`~numbers.Integral` (usually a long integer). Uses the
+ ``__trunc__`` method.
.. versionadded:: 2.6