fix some markup errors
diff --git a/Doc/api/concrete.tex b/Doc/api/concrete.tex
index cc3b2ab..f8cbc28 100644
--- a/Doc/api/concrete.tex
+++ b/Doc/api/concrete.tex
@@ -170,14 +170,14 @@
\begin{cfuncdesc}{unsigned long}{PyInt_AsUnsignedLongMask}{PyObject *io}
Will first attempt to cast the object to a \ctype{PyIntObject} or
- \ctypes{PyLongObject}, if it is not already one, and then return its
+ \ctype{PyLongObject}, if it is not already one, and then return its
value as unsigned long. This function does not check for overflow.
\versionadded{2.3}
\end{cfuncdesc}
\begin{cfuncdesc}{unsigned long}{PyInt_AsUnsignedLongLongMask}{PyObject *io}
Will first attempt to cast the object to a \ctype{PyIntObject} or
- \ctypes{PyLongObject}, if it is not already one, and then return its
+ \ctype{PyLongObject}, if it is not already one, and then return its
value as unsigned long long, without checking for overflow.
\versionadded{2.3}
\end{cfuncdesc}