GB/T 34839-2017/ISO 10552:2014.Timekeeping instruments- Designs and dimensions of crowns and sealed ...
GB/T 34839-2017/ISO 10552 :2014 计时仪器柄头和密封管的设计和尺寸
GB/T 34839-2017/ISO 10552 :2014.Timekeeping instruments- Designs and dimensions of crowns and sealed...