DIN 21550:1988-05 Mine support; roof bars for single props; testing, requirements
标准编号:DIN 21550:1988-05
英文标题:Mine support; roof bars for single props; testing, requirements
德文标题:Grubenausbau; Stahlkappen für Einzelstempel; Prüfung, Anforderungen
发布日期:1988-05
标准预览图


