Gear, J., & Gear, R. (2007). Cambridge preparation for the TOEFL test (4th ed.). Cambridge University Press.

Gear, Jolene, and Robert Gear. Cambridge Preparation for the TOEFL Test. 4th ed. Cambridge ; New York ; New Delhi: Cambridge University Press, 2007.

Gear, Jolene, and Robert Gear. Cambridge Preparation for the TOEFL Test. 4th ed. Cambridge University Press, 2007.