1<!ELEMENT document ANY>
2<!ELEMENT title (#PCDATA)>
3<!ELEMENT publisher (#PCDATA)>
4<!ELEMENT book (#PCDATA)>
5<!ELEMENT bookurn (#PCDATA)>
6<!ATTLIST book price CDATA "$100">
7<!ATTLIST book author CDATA "Herold">
8<!ATTLIST book number ID #REQUIRED>
9<!ATTLIST bookurn xmlns CDATA "10">
10<!ATTLIST bookurn xmlns:isbn CDATA "10">
11<!ENTITY w "William">
12<!ENTITY s "Shakespeare">
13