Barlow, G. (1921). Earthwork (9th ed.). Superintendent, Government Press.
Cita Chicago (17th ed.)Barlow, G.T. Earthwork. 9th ed. Allahabad: Superintendent, Government Press, 1921.
Cita MLA (9th ed.)Barlow, G.T. Earthwork. 9th ed. Superintendent, Government Press, 1921.
Atenció: Aquestes cites poden no estar 100% correctes.