CONNOLLY J P AND OHARRA C MINERAL WEALTH OF THE BLACK HILLSOOL OF MINES BULL 16 P 204LINCOLN F L THE MINING INDUSTRY OF S DAKOTA,S D SCHOOL OF MIL 17 P 100RUNNER J J AND HARTMANN M L 1918 THE OCCURRENCE CHEMISTRY MEY AND USES OF TUNGSTEN WITH SPECIAL REFERENCE TO THE BLACK HSOUTH DAKOTA,S D SCHOOL OF MINES BULL 12 265 PP.SOUTH DAK STATE MINE INSPECTOR ANN REPT FOR 1917 PP 21 22.SOUTH DAK PLANNING BOARD TUNGSTEN MINING IN S DAKOTA 1936 PU S BUMINES STAFF REGION V 1954 BLACK HILLS MINERAL ATLAS.SINF CIRC 7688 P 74