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

<xsd:element name="students" type="studentsType"/>

<xsd:complexType name="studentsType">
  <xsd:sequence>
    <xsd:element name="student" type="studentType"
                 minOccurs="0" maxOccurs="unbounded"/>
  </xsd:sequence>
</xsd:complexType>

<xsd:complexType name="studentType">
  <xsd:sequence>
    <xsd:element name="sname" type="xsd:string"/>
    <xsd:element name="phone" type="xsd:string"
                 minOccurs="0" maxOccurs="unbounded"/>
    <xsd:element name="email" type="xsd:string"/>
  </xsd:sequence>
</xsd:complexType>

</xsd:schema>