Cita APA

Helmuth, R., & Helmuth, R. (1987). Fly ash in cement and concrete. Illinois: Portland Cement Association.

Citación estilo Chicago

Helmuth, Richard, y Richard Helmuth. Fly Ash in Cement and Concrete. Illinois: Portland Cement Association, 1987.

Cita MLA

Helmuth, Richard, y Richard Helmuth. Fly Ash in Cement and Concrete. Illinois: Portland Cement Association, 1987.

Precaución: Estas citas no son 100% exactas.