Collins UK. (2018). Cambridge IGCSE® English Workbook (Cambridge International Examinations) ("Third Edition, Third edition".). HarperCollins UK.
Chicago Style aipamenaCollins UK. Cambridge IGCSE® English Workbook (Cambridge International Examinations). "Third Edition, Third edition". HarperCollins UK, 2018.
MLA aipamenaCollins UK. Cambridge IGCSE® English Workbook (Cambridge International Examinations). "Third Edition, Third edition". HarperCollins UK, 2018.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.