http://www.middlesboroughhistory.com http://www.coaleducation.org/coalhistory/coaltowns/midborro.htm
Va. Iron, Coal & Coke Co., Middlesboro, KY. From the Postcard Collection, University of Kentucky Special Collections. Accession number 2008ms016. http://kdl.kyvl.org/catalog/xt7x696zwx82_1_4057