Cita APA (7a ed.)

Crystal, D. (1997). English as a global language. Univ. Pr.

Cita Chicago Style (17a ed.)

Crystal, David. English as a Global Language. Cam.: Univ. Pr, 1997.

Cita MLA (9a ed.)

Crystal, David. English as a Global Language. Univ. Pr, 1997.