C:\test>junk
<book>
  <author>Book 1 author 1</author>
  <author>Book 1 author 2</author>
  <isbn>Book1ISBN</isbn>
  <title>Book 1 title</title>
</book>

<book>
  <author>Book 2 author 1</author>
  <author>Book 2 author 2</author>
  <isbn>Book2ISBN</isbn>
  <title>Book 2 title</title>
</book>

<book>
  <author>Book 3 author 1</author>
  <author>Book 3 author 2</author>
  <author>Book 3 author 3</author>
  <isbn>Book3ISBN</isbn>
  <title>Book 3 title</title>
</book>