Cita APA (7th ed.)

Allen, E. F. How to write and speak effective english. A modern guide to good form.

Cita Chicago (17th ed.)

Allen, Edward Frank. How to Write and Speak Effective English. A Modern Guide to Good Form.

Cita MLA (8th ed.)

Allen, Edward Frank. How to Write and Speak Effective English. A Modern Guide to Good Form.