Cita APA (7a ed.)

Downie, M. (1998). Freeform: Student's book 1B. Santillana.

Cita Chicago Style (17a ed.)

Downie, Michael. Freeform: Student's Book 1B. Buenos Aires: Santillana, 1998.

Cita MLA (9a ed.)

Downie, Michael. Freeform: Student's Book 1B. Santillana, 1998.