Area of unsupported roof in coal mines; conditions and factors for consideration.

Bibliographic Details
Other Authors:	Paul, J. W. (James Washington)
Format:	Government Document eBook
Language:	English
Published:	Washington, D.C. : [publisher not identified], 1927.
Series:	Mines Bur. Info. Circ. No. 6040
Subjects:	Coal mines and mining. Electronic books.
Online Access:	Connect to the full text of this electronic document

Description
Item Description:	Record is based on bibliographic data in ProQuest U.S. Executive Branch Documents, 1910-1932. Reuse except for individual research requires license from ProQuest, LLC. Electronic resource.
Physical Description:	1 online resource (3 pages)
Format:	System requirements: PDF reader software.