APA

Hashemi L., Thomas B., . (2011). Cambridge Grammar for PET. Cambridge: Cambridge University Press.

Chicago

Hashemi L, Thomas B, . 2011. Cambridge Grammar for PET. Cambridge: Cambridge University Press.

Harvard

Hashemi L., Thomas B., . (2011). Cambridge Grammar for PET. Cambridge: Cambridge University Press.

MLA

Hashemi L, Thomas B, . Cambridge Grammar for PET. Cambridge: Cambridge University Press. 2011.