add a missing Oxford comma

P5/Source/Guidelines/en/TS-TranscriptionsofSpeech.xml

@@ -500,7 +500,7 @@ section <ptr target="#TSSAPA"/>.
 <p>An utterance may contain either running text, or text within which
 other basic structural elements are nested.  Where such nesting occurs,
 the <att>who</att> attribute is considered to be inherited for the
-elements <gi>pause</gi>, <gi>vocal</gi>, <gi>shift</gi> and
+elements <gi>pause</gi>, <gi>vocal</gi>, <gi>shift</gi>, and
 <gi>kinesic</gi>; that is, a pause or shift (etc.) within an utterance
 is regarded as being produced by that speaker only, while a pause
 between utterances applies to all speakers.
@@ -1472,4 +1472,4 @@ to divide a transcribed text up into meaningful analytic sections.
     <include xmlns="http://www.w3.org/2001/XInclude" href="../../Specs/annotationBlock.xml"/>
   </specGrp>
 </div>
-</div>
+</div>