<xs:schema xmlns:xs=“www.w3.org/2001/XMLSchema”>
<xs:group name="name"> <xs:choice> <xs:element name="name" type="xs:string"/> <xs:sequence> <xs:element name="first-name" type="xs:string"/> <xs:element name="middle-name" type="xs:string" minOccurs="0"/> <xs:element name="last-name" type="xs:string"/> </xs:sequence> </xs:choice> </xs:group> <xs:element name="author"> <xs:complexType> <xs:group ref="name"/> </xs:complexType> </xs:element>
</xs:schema>