Standardized Construction of Mine Ventilating Doors

Author:	Hartley, J. C.
Year:	1944
Document Type:	N/A
SUDOC:	I 28.27:7280
Series:	Information circular (United States. Bureau of Mines)
Report Number:	I. C. 7280
Subjects:	Mine ventilation.
	Coal mines and mining -- Safety measures.
Link:	http://digital.library.unt.edu/ark:/67531/metadc67029/