fixed-term contract work, agency work, atypical work, workers representative, right of collective action, right of cllective bargaining, right to organse, trade unions, employers, workers, fluctuation of contract of employment, legal incidents of contract of employment, contract of employment, right to work, 有期契約労働, 派遣労働, 非正規労働, 従業員代表制, 団体行動権, 団体交渉権, 団結権, 労働組合, 使用者概念, 労働者概念, 雇用保障法, 労働契約の変動, 附随義務, 雇用契約, 労働契約, 労働権