Doff, A., & Goldstein, B. (2011). English unlimited: Advanced. Coursebook with e-Portfolio. C1. Cambridge University Press.
Citazione stile Chigago Style (17a edizione)Doff, Adrian, e Ben Goldstein. English Unlimited: Advanced. Coursebook with E-Portfolio. C1. Cambridge: Cambridge University Press, 2011.
Citatione MLA (9a ed.)Doff, Adrian, e Ben Goldstein. English Unlimited: Advanced. Coursebook with E-Portfolio. C1. Cambridge University Press, 2011.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.