https://petermetz.de/ 2026-05-30T21:07:42+00:00 https://petermetz.de/ https://petermetz.de/lib/tpl/bootstrap3/images/favicon.ico text/html 2022-03-20T06:27:45+00:00 Anonymous (anonymous@undisclosed.example.com) https://petermetz.de/rtd:refs:eng:construction:start?rev=1647757665&do=diff Construction Materials and Techniques Underground Construction Techniques W. W. Staley. 1962. Timbering and Support of Underground Workings for Small Mines. Bulletin No. 21, Idaho Bureau of Mines and Geology. ID, US. Available from idahogeology.org/pub/Bulletins/B-21.pdf. Mike Oehler. 1983. The Low Cost Underground House Workshop. Video Series. Mole Publishing Co., ID, US. Available from