Retrieving Requester Email Address with REST API?

Hello.

How do I retrieve a requester e-mail address from a ticket with the API? According to the documentation, the only fields returned when getting request information are:

<parameter>
<name>workorderid</name>
<value><requestid></value>
</parameter>
</parameter>
<name>requester</name>
<value>administrator</value>
</parameter>
<name>createdby</name>
<value>administrator</value>
</parameter>
</parameter>
<name>createdtime</name>
<value>12321434324324</value>
</parameter>
</parameter>
<name>duebytime</name>
<value>11234321412454</value>
</parameter>
</parameter>
<name>subject</name>
<value>subject</value>
</parameter>
</parameter>
<name>technician</name>
<value>administrator</value>
</parameter>
</parameter>
<name>priority</name>
<value>High</value>
</parameter>
</parameter>
<name>status</name>
<value>open</value>
</parameter>
</parameter>
<name>isoverdue</name>
<value>false</value>
</parameter>
</record>
<record URL="http://localhost:8080/sdpapi/request/<requestid>"
<parameter>
<name>workorderid</name>
<value><requestid></value>
<parameter>
<name>requester</name>
<value>administrator</value>
<parameter>
<parameter>
<name>createdby</name>
<value>administrator</value>
<parameter>
<parameter>
<name>createdtime</name>
<value>1232143323543</value>
<parameter>
<parameter>
<name>duebytime</name>
<value>1123432143534</value>
<parameter>
<parameter>
<name>subject</name>
<value>subject</value>
<parameter>
<parameter>
<name>technician</name>
<value>administrator</value>
<parameter>
<parameter>
<name>priority</name>
<value>High</value>
<parameter>
<parameter>
<name>status</name>
<value>open</value>
<parameter>
<parameter>
<name>isoverdue</name>
<value>false</value>
<parameter>