Cita APA (7a ed.)
Williams, S. R. (1942). Hardness and Hardness Measurements. American Society for Metals.
Cita Chicago Style (17a ed.)
Williams, Samuel R. Hardness and Hardness Measurements. Clevland: American Society for Metals, 1942.
Cita MLA (9a ed.)
Williams, Samuel R. Hardness and Hardness Measurements. American Society for Metals, 1942.
Precaución: Estas citas no son 100% exactas.