public static function getExistentTranslations($nativeNames = TRUE) {
		
		$columnName = $nativeNames ? 'native_name' : 'english_name';
		
		$query =
		'SELECT lo.*, CONCAT(la.code, "-", co.code) AS representation,' .
		' CONCAT(la.' . $columnName . ', " (", co.' . $columnName . ', ")") AS language_country' .
		' FROM `locales` AS lo' .
		' INNER JOIN `languages` AS la ON lo.language_id = la.id' .
		' INNER JOIN `countries` AS co ON lo.country_id = co.id' .
		' ORDER BY la.' . $columnName;
		
		// all registered Locales with native or english language(country) name
		$locales = Locale::getObjectsByQuery($query);
		
		// list all common translation files
		$files = Utilities::getDirectoryFilenames('translations');
		
		$existents = array();
		
		foreach ($files as $file) {
			
			$fileRepresentation = substr($file, 0, strlen($file)-4);
			
			foreach ($locales as $locale) {
				if ($locale->representation == $fileRepresentation) {
					$existents[] = $locale;
					continue;
				}
			}
			
		}
		
		return $existents;
		
	}