Drivage development and support of roadways and faces in deep mines - 750 metres and over - and consequently in more difficult mining, geological and atmospheric conditions / transmitted by the Government of Poland.
1981
详细记录
符号[E/ECE/]COAL/GE.4/R.19/Add.1
标题Drivage development and support of roadways and faces in deep mines - 750 metres and over - and consequently in more difficult mining, geological and atmospheric conditions / transmitted by the Government of Poland.
作者Poland
日期Geneva : UN, 6 Nov. 1981.
描述
17 p. : tables