<prices>
    <book>
        <title>Advanced Programming in the Unix environment</title>
        <source>www.amazon.com</source>
        <price>65.95</price>
    </book>
    <book>
        <title>Advanced Programming in the Unix environment</title>
        <source>www.bn.com</source>
        <price>65.95</price>
    </book>
    <book>
        <title>TCP/IP Illustrated</title>
        <source>www.amazon.com</source>
        <price>65.95</price>
    </book>
    <book>
        <title>TCP/IP Illustrated</title>
        <source>www.bn.com</source>
        <price>65.95</price>
    </book>
    <book>
        <title>Data on the Web</title>
        <source>www.amazon.com</source>
        <price>34.95</price>
    </book>
    <book>
        <title>Data on the Web</title>
        <source>www.bn.com</source>
        <price>39.95</price>
    </book>
</prices>
