<?xml version="1.0"?>
<schema xmlns="http://www.w3.org/2001/XMLSchema"
        xmlns:t="test"
        targetNamespace="test">

<element name="Book" type="string"/>

<element name="Library">
  <complexType>
    <sequence>
       <element ref="t:Book" minOccurs="3" maxOccurs="3"/>
       <element ref="t:Book" minOccurs="4" maxOccurs="4"/>
    </sequence>
  </complexType>
</element>

</schema>
