Out of line Link example
<COURSE xmlns:xlink="http://www.w3.org/1999/xlink"
xlink:type="extended">
<TOC xlink:type="locator" xlink:href="index.xml" xlink:role="index"/>
<CLASS xlink:type="locator" xlink:href="week1.xml" xlink:role="class"/>
<CLASS xlink:type="locator" xlink:href="week2.xml" xlink:role="class"/>
<CLASS xlink:type="locator" xlink:href="week3.xml" xlink:role="class"/>
<CLASS xlink:type="locator" xlink:href="week4.xml" xlink:role="class"/>
<CLASS xlink:type="locator" xlink:href="week5.xml" xlink:role="class"/>
<CLASS xlink:type="locator" xlink:href="week6.xml" xlink:role="class"/>
<CLASS xlink:type="locator" xlink:href="week7.xml" xlink:role="class"/>
<CLASS xlink:type="locator" xlink:href="week8.xml" xlink:role="class"/>
<CLASS xlink:type="locator" xlink:href="week9.xml" xlink:role="class"/>
<CLASS xlink:type="locator" xlink:href="week10.xml" xlink:role="class"/>
<CLASS xlink:type="locator" xlink:href="week11.xml" xlink:role="class"/>
<CLASS xlink:type="locator" xlink:href="week12.xml" xlink:role="class"/>
<CLASS xlink:type="locator" xlink:href="week13.xml" xlink:role="class"/>
<CONNECTION xlink:type="arc" from="index" to="class"/>
<CONNECTION xlink:type="arc" from="class" to="index"/>
</COURSE>