Allen, E. (1955). How to write & speak effective english. Fawcett.
Citazione stile Chigago Style (17a edizione)Allen, Edwards. How to Write & Speak Effective English. New York: Fawcett, 1955.
Citatione MLA (9a ed.)Allen, Edwards. How to Write & Speak Effective English. Fawcett, 1955.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.