Cita APA (7th ed.)

Alexander, L. G. (1975). Mainline: Skills A, students' book (1a. ed.). Longman.

Cita Chicago (17th ed.)

Alexander, Louis George. Mainline: Skills A, Students' Book. 1a. ed. Londres: Longman, 1975.

Cita MLA (9th ed.)

Alexander, Louis George. Mainline: Skills A, Students' Book. 1a. ed. Longman, 1975.