Cita APA

SMITH, C. B., & WARDHAUGH, R. (1980). Signals. Macmillan.

Citación estilo Chicago

SMITH, Carl B., and ROnald WARDHAUGH. Signals. New York: Macmillan, 1980.

Cita MLA

SMITH, Carl B., and ROnald WARDHAUGH. Signals. Macmillan, 1980.