APA

Cowley J., Fowley، Jeff, .quack . quack . quack. London: Heinemann Educational Books.

Chicago

Cowley Joy, Fowley، Jeff, .quack . quack . quack. London: Heinemann Educational Books.

Harvard

Cowley J., Fowley، Jeff, .quack . quack . quack. London: Heinemann Educational Books.

MLA

Cowley Joy, Fowley، Jeff, .London: Heinemann Educational Books. .