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| backfilling of workings space (1) |
| combined backfilling (1) |
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| ore mining (1) |
| ores mining safety (1) |
| stoped excavation (1) |
| workings space (1) |
| backfilling of workings space (1) |
| combined backfilling (1) |
| isolating cross-connection (1) |
| ore mining (1) |
| ores mining safety (1) |
| stoped excavation (1) |
| workings space (1) |