APA
Fash S., . (2013). Thumbs up Teachers guide Level 4 booklet 2. México: México D.F: Richmond.
Chicago
Fash Sarah, . 2013. Thumbs up Teachers guide Level 4 booklet 2. México: México D.F: Richmond.
Harvard
Fash S., . (2013). Thumbs up Teachers guide Level 4 booklet 2. México: México D.F: Richmond.
MLA
Fash Sarah, . Thumbs up Teachers guide Level 4 booklet 2. México: México D.F: Richmond. 2013.