Dummett, P. (2013). Life: Upper intermediate. Workbook (1a. ed.). National Geographic.
Chicago Style (17th ed.) ZitazioaDummett, Paul. Life: Upper Intermediate. Workbook. 1a. ed. Hampshire: National Geographic, 2013.
MLA (9th ed.) ZitazioaDummett, Paul. Life: Upper Intermediate. Workbook. 1a. ed. National Geographic, 2013.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.