Automatic update

--- a/doc-src/Ref/ref.bbl	Wed Apr 30 16:33:43 1997 +0200
+++ b/doc-src/Ref/ref.bbl	Wed Apr 30 16:36:38 1997 +0200
@@ -58,6 +58,6 @@
 F.~J. Pelletier.
 \newblock Seventy-five problems for testing automatic theorem provers.
 \newblock {\em Journal of Automated Reasoning}, 2:191--216, 1986.
-\newblock Errata, JAR 4 (1988), 235--236.
+\newblock Errata, JAR 4 (1988), 235--236 and JAR 18 (1997), 135.
 
 \end{thebibliography}