See T. M. Megaw and J. V. Bartlett, Tunnels (1981–82); B. Stack, Handbook of Mining and Tunnelling Machinery (1982); Approaching the 21st Century (1987).
Sections in this article:
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.
See more Encyclopedia articles on: Technology: Terms and Concepts