diff --git a/Doc/ext.tex b/Doc/ext.tex
index bfcff50..6626130 100644
--- a/Doc/ext.tex
+++ b/Doc/ext.tex
@@ -37,6 +37,13 @@
 functions and modules (both built-in and written in Python) that give
 the language its wide application range.
 
+For a detailed description of the whole Python/C API, see the separate
+Python/C API Reference Manual.  \strong{Note:} While that manual is
+still in a state of flux, it is safe to say that it is much more up to
+date than the manual you're reading currently (which has been in need
+for an upgrade for some time now).
+
+
 \end{abstract}
 
 \pagebreak