APA (7th ed.) Citation

Kostakou, A. (1998). The Leaders: Upper intermediate teacher's book. Hillside Press.

Chicago Style (17th ed.) Citation

Kostakou, A. The Leaders: Upper Intermediate Teacher's Book. Athens: Hillside Press, 1998.

MLA (9th ed.) Citation

Kostakou, A. The Leaders: Upper Intermediate Teacher's Book. Hillside Press, 1998.