| Reference | {Deposit:: FRYKLUND AND OTHERS, 1954, NIOBIUM AND TITANIUM AT MAGNET COVE AND POTASH SULPHUR SPRINGS, ARKANSAS, U. S. G. S. BULL. 1015 - B}{Deposit:: PARKER, R.L., AND ADAMS, J.W., USGS PROF. PAPER 820}{Reserve-Resource:: PARKER, R. L., AND ADAMS, J. W., U. S. G. S. PROF. PAPER 820} |