APA

Cullen P., . (2008). Cambridge Vocabulary for IELTS. Cambridge: Cambridge University Press.

Chicago

Cullen P, . 2008. Cambridge Vocabulary for IELTS. Cambridge: Cambridge University Press.

Harvard

Cullen P., . (2008). Cambridge Vocabulary for IELTS. Cambridge: Cambridge University Press.

MLA

Cullen P, . Cambridge Vocabulary for IELTS. Cambridge: Cambridge University Press. 2008.