<?php
libxml_use_internal_errors(true);
$myXMLData =
'<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<reference:reference
    xmlns:seller="http://services.mobile.de/schema/seller"
    xmlns:ad="http://services.mobile.de/schema/ad"
    xmlns:financing="http://services.mobile.de/schema/common/financing-1.0"
    xmlns:reference="http://services.mobile.de/schema/reference"
    xmlns:resource="http://services.mobile.de/schema/resource">
    <reference:item key="Cabrio" url="https://services.mobile.de/refdata/categories/Cabrio">
        <resource:local-description xml-lang="en">Cabriolet / Roadster</resource:local-description>
    </reference:item>
    <reference:item key="EstateCar" url="https://services.mobile.de/refdata/categories/EstateCar">
        <resource:local-description xml-lang="en">Estate Car</resource:local-description>
    </reference:item>
    <reference:item key="OffRoad" url="https://services.mobile.de/refdata/categories/OffRoad">
        <resource:local-description xml-lang="en">Off-road Vehicle/Pickup Truck</resource:local-description>
    </reference:item>
    <reference:item key="Limousine" url="https://services.mobile.de/refdata/categories/Limousine">
        <resource:local-description xml-lang="en">Saloon</resource:local-description>
    </reference:item>
    <reference:item key="SmallCar" url="https://services.mobile.de/refdata/categories/SmallCar">
        <resource:local-description xml-lang="en">Small Car</resource:local-description>
    </reference:item>
    <reference:item key="SportsCar" url="https://services.mobile.de/refdata/categories/SportsCar">
        <resource:local-description xml-lang="en">Sports Car/Coupe</resource:local-description>
    </reference:item>
    <reference:item key="Van" url="https://services.mobile.de/refdata/categories/Van">
        <resource:local-description xml-lang="en">Van / Minibus</resource:local-description>
    </reference:item>
    <reference:item key="OtherCar" url="https://services.mobile.de/refdata/categories/OtherCar">
        <resource:local-description xml-lang="en">Other</resource:local-description>
    </reference:item>
</reference:reference>';

$xml = simplexml_load_string($myXMLData);
if ($xml === false) {
    echo "Failed loading XML: ";
    foreach(libxml_get_errors() as $error) {
        echo "<br>", $error->message;
    }
} else {
    print_r($xml);
    foreach($xml->{'reference:item'} as $item){
        echo $item->{'resource:local-description'};
    }
}
?>