@@ 2288,7 2288,10 @@ Join me on my path into Guile.
 #+latex: \vspace*{\stretch{1}}
 
 #+latex: \begin{center}
-#+latex: \colorbox{white}{\EANisbn[978-3-7375-6840-1]}
+# ebook ISBN:
+# #+latex: \colorbox{white}{\EANisbn[978-3-7375-6976-7]}
+# printed book ISBN:
+# #+latex: \colorbox{white}{\EANisbn[978-3-7375-6840-1]}
 
 #+latex: \vspace*{\baselineskip}