APA

Hughes J., Stephenson H. & Dummet P. (2013). Life: pre-intermediate. Hampshire: Cengage Learning; National Geographic Learning.

Chicago

Hughes John, Stephenson Helen and Dummet Paul. 2013. Life: pre-intermediate. Hampshire: Cengage Learning; National Geographic Learning.

Harvard

Hughes J., Stephenson H. and Dummet P. (2013). Life: pre-intermediate. Hampshire: Cengage Learning; National Geographic Learning.

MLA

Hughes John, Stephenson Helen and Dummet Paul. Life: pre-intermediate. Hampshire: Cengage Learning; National Geographic Learning. 2013.