avail 

Availability and access - REQUIRED use for URL, online database, ftp address,
email, etc.;
Examples:
    - Available from Internet: http://www.epoline.org
    - Available from DIALOG Information Systems, Palo Alto (Calif.)
    - Available from: <http://www.ejb.org/content/vol2/issue3/full/3/index.html>. 
    - Available from Bell and Howell Information and Learning via e-mail to: 
      <umi@ppp.nasionet.net>.

Element Information

Model

Source 

<xs:element name="avail" type="availType">
  <xs:annotation>
    <xs:documentation>Availability and access - REQUIRED use for URL, online database, ftp address, email, etc.; Examples: - Available from Internet: http://www.epoline.org - Available from DIALOG Information Systems, Palo Alto (Calif.) - Available from: <http://www.ejb.org/content/vol2/issue3/full/3/index.html>. - Available from Bell and Howell Information and Learning via e-mail to: <umi@ppp.nasionet.net>.</xs:documentation>
  </xs:annotation>
</xs:element>

Sample