APA

Cullen P., . (2012). Vocabulary for IELTS. : Cambridge University Press.

Chicago

Cullen Pauline, . 2012. Vocabulary for IELTS. : Cambridge University Press.

Harvard

Cullen P., . (2012). Vocabulary for IELTS. : Cambridge University Press.

MLA

Cullen Pauline, . Vocabulary for IELTS. : Cambridge University Press. 2012.