Biber, D., Conrad, S., & Leech, G. N. (2002). Longman student grammar of spoken and written English. Pearson Education Limited.
Citazione stile Chigago Style (17a edizione)Biber, Douglas, Susan Conrad, e Geoffrey N. Leech. Longman Student Grammar of Spoken and Written English. Londres: Pearson Education Limited, 2002.
Citatione MLA (9a ed.)Biber, Douglas, et al. Longman Student Grammar of Spoken and Written English. Pearson Education Limited, 2002.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.