protected function getWeekWordsUnitsAndShortcuts ($lang) {
		if (!isset($this->weekWords[$lang])) {
			if (isset(static::$WeekWordsDefault[$lang])) {
				$this->weekWords[$lang] = explode(',', static::$WeekWordsDefault[$lang]);
			} else {
				$this->weekWords[$lang] = [];
			}
		}
		if (!$this->units) 
			$this->units = explode(',', static::$UnitsDefault);
		if (!isset($this->shortcuts[$lang])) {
			if (isset(static::$ShortcutsDefault[$lang])) {
				$shortcuts = [];
				/** @var $shortcutsLocalized array */
				foreach (static::$ShortcutsDefault[$lang] as $shortcutsLocalized) 
					foreach ($shortcutsLocalized as $shortcut)
						$shortcuts[$shortcut] = str_replace(' ', '&nbsp;', $shortcut);
				$this->shortcuts[$lang] = & $shortcuts;
			} else {
				$this->shortcuts[$lang] = [];
			}
		}
		return [
			$this->weekWords[$lang], 
			$this->units, 
			$this->shortcuts[$lang]
		];
	}