Order by Best Match A - Z Z - A Oldest Newest Go 1 publication found Authors: Tweedy, G.A. Filter Results Mineral Exploration and Development Atlas of the Upper Mississippi Valley District Open-file report; contains unpublished data that has not yet been peer-reviewed. WOFR1952-02 Mineral Exploration and Development Atlas of the Upper Mississippi Valley District Tweedy, G.A.; Heyl, A.V.; 1952 Report: 52 p.