APA

Hopkins A., Potter J., . (1999). Look Ahead 1. Classroom course. Harlow: Longman.

Chicago

Hopkins A, Potter J, . 1999. Look Ahead 1. Classroom course. Harlow: Longman.

Harvard

Hopkins A., Potter J., . (1999). Look Ahead 1. Classroom course. Harlow: Longman.

MLA

Hopkins A, Potter J, . Look Ahead 1. Classroom course. Harlow: Longman. 1999.