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 permies.com.
Mike Oehler. 1997. The Fifty Dollar and Up Underground House Book. Mole Publishing Co., ID, US. ISBN 0-442-27311-8. Available from undergroundhousing.com (paper) or permies.com (digital).
Mike Oehler. 2007. The Earth-Sheltered Solar Greenhouse Book. Mole Publishing Co., ID, US. ISBN 9780960446407. Available from undergroundhousing.com (paper) or permies.com (digital).