Downie, M. (1998). Freeform: Student's book 1A. Santillana.
Cita Chicago Style (17a ed.)Downie, Michael. Freeform: Student's Book 1A. Buenos Aires: Santillana, 1998.
Cita MLA (9a ed.)Downie, Michael. Freeform: Student's Book 1A. Santillana, 1998.
警告：这些引文格式不一定是100％准确.