Draft Document - Petroleum, petrochemical and natural gas industries - Safety of machineries - Powered elevators (ISO/DIS 20321:2017); German and English version prEN ISO 20321:2017
文件草案——石油、石化和天然气工业——机械安全——动力电梯(ISO/DIS 20321-2017);德文版和英文版prEN ISO 20321:2017