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