Before you get started with this project you need to make a backup copy of your original XML file. (books.xml) You can save the file as project2.xml so you can use it for this project. For this project you will focus on adding an entity to your xml document.
You will work with the Publisher field of your XML document. Publishing companies seem to merge a lot and change their names. It would be nice to only have to change the publisher one time if this XML file grew to five hundred or more books. I want you to create an external entity file that we can use to automatically update publishers. Connect the project2.xml file to the external entity.