Citazione Stile APA (7a Edizione)

Lock, G. Functional english grammar. An introduction for second language teachers (2a ed.).

Citazione stile Chigago Style (17a edizione)

Lock, Graham. Functional English Grammar. An Introduction for Second Language Teachers. 2a ed.

Citatione MLA (8a ed.)

Lock, Graham. Functional English Grammar. An Introduction for Second Language Teachers. 2a ed.