APA (7th ed.) Citation

British Broadcasting Corporation, Stewart, D., & Harewood, D. (2012). Horizon. British Broadcasting Corporation (BBC).

Chicago Style (17th ed.) Citation

British Broadcasting Corporation, David Stewart, and David Harewood. Horizon. London, England: British Broadcasting Corporation (BBC), 2012.

MLA (9th ed.) Citation

British Broadcasting Corporation, et al. Horizon. British Broadcasting Corporation (BBC), 2012.