Doff, A., Thaine, C., Stranks, J., Lewis-Jones, P., & Puchta, H. (2022). Empower B1+: Intermediate Student's Book with eBook (Second edition.). Cambridge University Press.
Chicago-viite (17. p.)Doff, Adrian, Craig Thaine, Jeff Stranks, Peter Lewis-Jones, ja Herbert Puchta. Empower B1+: Intermediate Student's Book with EBook. Second edition. Cambridge, United Kingdom: Cambridge University Press, 2022.
MLA-viite (9. p.)Doff, Adrian, et al. Empower B1+: Intermediate Student's Book with EBook. Second edition. Cambridge University Press, 2022.
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