APA-referens (7:e uppl.)

Douglas, E. S., Girimonti, S., & Samuel, J. (2019). C1 skills training: The five, themed units give you extensive skills practice to up your level or prepare your exams. Editorial Tébar Flores.

Chicago-referens (17:e uppl.)

Douglas, Elisabeth S., Silvia Girimonti, och Julia Samuel. C1 Skills Training: The Five, Themed Units Give You Extensive Skills Practice to Up Your Level or Prepare Your Exams. Madrid, España: Editorial Tébar Flores, 2019.

MLA-referens (9:e uppl.)

Douglas, Elisabeth S., et al. C1 Skills Training: The Five, Themed Units Give You Extensive Skills Practice to Up Your Level or Prepare Your Exams. Editorial Tébar Flores, 2019.