Fix obvious typos.
diff --git a/Doc/api/abstract.tex b/Doc/api/abstract.tex
index 166884b..8f1ce93 100644
--- a/Doc/api/abstract.tex
+++ b/Doc/api/abstract.tex
@@ -876,7 +876,7 @@
Returns a pointer to a read-only memory location useable as character-
based input. The \var{obj} argument must support the single-segment
character buffer interface. On success, returns \code{1}, sets
- \var{buffer} to the memory location and \var{buffer} to the buffer
+ \var{buffer} to the memory location and \var{buffer_len} to the buffer
length. Returns \code{0} and sets a \exception{TypeError} on error.
\versionadded{1.6}
\end{cfuncdesc}
@@ -887,7 +887,7 @@
Returns a pointer to a read-only memory location containing
arbitrary data. The \var{obj} argument must support the
single-segment readable buffer interface. On success, returns
- \code{1}, sets \var{buffer} to the memory location and \var{buffer}
+ \code{1}, sets \var{buffer} to the memory location and \var{buffer_len}
to the buffer length. Returns \code{0} and sets a
\exception{TypeError} on error.
\versionadded{1.6}
@@ -905,7 +905,7 @@
Returns a pointer to a writeable memory location. The \var{obj}
argument must support the single-segment, character buffer
interface. On success, returns \code{1}, sets \var{buffer} to the
- memory location and \var{buffer} to the buffer length. Returns
+ memory location and \var{buffer_len} to the buffer length. Returns
\code{0} and sets a \exception{TypeError} on error.
\versionadded{1.6}
\end{cfuncdesc}