Doff, A., Smith, H., Thake, R., Brabben, C., & Lloyd, M. (2010). English unlimited: Pre-intermediate Teacher's Pack. B1. Cambridge University Press.
Citazione stile Chigago Style (17a edizione)Doff, Adrian, Howard Smith, Rachel Thake, Cathy Brabben, e Mark Lloyd. English Unlimited: Pre-intermediate Teacher's Pack. B1. Cambridge University Press, 2010.
Citatione MLA (9a ed.)Doff, Adrian, et al. English Unlimited: Pre-intermediate Teacher's Pack. B1. Cambridge University Press, 2010.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.