RE: referencing a schema fails

P.S.  Just to be clearer, I should have included my attempt at coding the
schema for the element containing both attributes and child elements:

<xsd:element name="review">
  <xsd:complexType>
  <xsd:attribute name="author" use="required" type="authorType" />
  <xsd:attribute name="completed" use="required" type="xsd:date" />
    <xsd:sequence>
          <xsd:element ref="blurb" />
          <xsd:element ref="exhibition" />
          <xsd:element ref="essay" />
          <xsd:element ref="images" />
        </xsd:sequence>
  </xsd:complexType>
</xsd:element>

John