public function getDereferenced()
    {
        if ($this->dereferenced_field) {
            return $this->dereferenced_field;
        }
        $f = preg_replace('/_id$/', '', $this->short_name);
        if ($f != $this->short_name) {
            return $f;
        }

        $f = $this->short_name.'_text';
        if ($this->owner->hasElement($f)) {
            return $f;
        }

        $f = $this->_unique($this->owner->elements, $f);
        $this->dereferenced_field = $f;

        return $f;
    }