http://pec.lib.wvu.edu/record/P51291931Memorial of John Littlefield Tilton. Serial issue. Issued as: <em>Bulletin of the Geological Society of America</em>, v.42 (1931).<br />Reger, David B. (David Bright), 1882-1958.Tilton, John Littlefield, b. 1863.14256