铁路下采煤的技术研究
Study on coal extraction under railroad
铁路下采煤实践
Practice of mining coal under railway
矿区铁路线下采煤技术
Coal Mining Technology under Railway in Mining Area
铁路无缝线路下采煤问题的研究
On the problems of mining under the continuous welded rails
铁路下采煤铁路下采煤铁路下采煤