TY - RPRT TI - Niobium (columbium) and titanium at Magnet Cove and Potash Sulphur Springs, Arkansas AU - Verne Charles Fryklund AU - R. S. Harner AU - E.P. Kaiser PY - 1953 DO - 10.3133/ofr5374 UR - https://pubs.usgs.gov/publication/ofr5374 ID - ofr5374 ER -