public static function loadLocales($langKey)
    {
        $data = null;
        $localesPath = self::vendorPath() . "/citation-style-language/locales/";
        $localeFile = $localesPath . "locales-" . $langKey . '.xml';
        if (file_exists($localeFile)) {
            $data = file_get_contents($localeFile);
        } else {
            $metadata = self::loadLocalesMetadata();
            if (!empty($metadata->{'primary-dialects'}->{$langKey})) {
                $data = file_get_contents($localesPath . "locales-" . $metadata->{'primary-dialects'}->{$langKey} . '.xml');
            }
        }

        return $data;
    }