https://www.blm.gov/documents/national-office/blm-library/report/petrographic-characterization-some-precambrian
Petrographic Characterization of Some Precambrian Crystalline Rocks from the Sondre Stromfjord...
As part of investigations of the nature and characteristics of rocks likely to been countered below the Inland Ice of interior Greenland, four samples...
from thecharacterizationprecambrian