Schiffrin, R. S. (1970). English in action: A course for spanish speaking commercial students. Longman.
Citazione stile Chigago Style (17a edizione)Schiffrin, R. S. English in Action: A Course for Spanish Speaking Commercial Students. Gran Bretaña: Longman, 1970.
Citatione MLA (9a ed.)Schiffrin, R. S. English in Action: A Course for Spanish Speaking Commercial Students. Longman, 1970.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.