diff --git a/cscweb.xsl b/cscweb.xsl
index 2424111..e6bfde0 100755
--- a/cscweb.xsl
+++ b/cscweb.xsl
@@ -268,7 +268,7 @@
 	<xsl:if test="position() mod 2 = 0">
 	  <xsl:attribute name="bgcolor">#cee6ff</xsl:attribute>
 	</xsl:if>
-	<td><a href="/office/books/{@isbn}.html"><xsl:value-of
+	<td><a href="/office/books/{translate(@isbn, ' ', '-')}.html"><xsl:value-of
 	select="@title"/><xsl:if test="@edition != ''"> (<xsl:value-of
 	select="@edition"/>)</xsl:if></a></td>
 	<td><xsl:value-of select="@author"/></td>