(1914). Coal age. McGraw-Hill.
Cita Chicago (17th ed.)Coal Age. New York: McGraw-Hill, 1914.
Cita MLA (9th ed.)Coal Age. McGraw-Hill, 1914.
Atenció: Aquestes cites poden no estar 100% correctes.
Cita APA (7th ed.)
(1914). Coal age. McGraw-Hill.
Cita Chicago (17th ed.)Coal Age. New York: McGraw-Hill, 1914.
Cita MLA (9th ed.)Coal Age. McGraw-Hill, 1914.