From Oswald J. Heinrich biography in "The Story of the Richmond, Virginia Coal Field and its Development 1700—1934," by F. R. Wadleigh. Washington, D.C: 1934, and "The Richmond Coal Basin, a Compilation in Three Parts," by Ira F. Davis and L. S. Evans. Library of Congress, Virginia State Library: 1938.
Compiled in "Historically Significant Sites on the Mid-Lothian Coal Mining Co. Tract In Chesterfield County, Virginia," a
collection of articles and excerpts compiled by Thomas F. Garner, Jr.
and located in the Midlothian Branch Library, and libraries of the
Virginia Historical Society and Chesterfield Historical Society.