Helix pressure gage to indicate roof bolt loads
| Image |  |
|---|---|
| Description | final contract report published in 1973 |
| Author/s |
author: anonymous |
| Publication date | January 1, 1973 |
| Language | English |
| Country of origin | |
| Wikipedia link | |
| Copyright status | |
| Missing/wrong data? | Edit Wikidata item |