GB/T 39336-2020沿空留巷高水材料巷旁袋式充填技术要求标准
英文:Technical requirement of roadside bag filling for gob-side entry retaining with high-water material GB/T 39336-2020介绍...
英文:Technical requirement of roadside bag filling for gob-side entry retaining with high-water material GB/T 39336-2020介绍...