Page View
Bureau of Mines / Minerals yearbook 1990
(1990)
Cunningham, Larry D.
Columbium (niobium) and tantalum, pp. 339-[358]
Page 339
![[page image]](http://images.library.wisc.edu/EcoNatRes/0004/0001/M/0347.gif)
As a work of the United States government, this material is in the public domain.| For information on re-use see: http://digital.library.wisc.edu/1711.dl/Copyright




