"Baltimore and Ohio Railroad Company Eastern Lines distribution of cars for coal loading, June, 1923, and mine ratings effective July 16, 1923."; "Baltimore and Ohio Railroad Company. Eastern Lines."; "Baltimore and Ohio Railroad Company."; "Coal mines and mining--United States.", "Coal transportation--United States."; "Baltimore and Ohio Railroad Company. Eastern Lines."; "1923"; "Serial issue. Issued as: Baltimore and Ohio Railroad Company. Eastern Lines. Bulletin, no.6-B."; ""; "P17648"; "pec"; "Coal transportation--United States.", "Baltimore and Ohio Railroad Company.", "Coal mines and mining--United States."; "14256"; .