1. Alberta Education. Biology 20–30. Edmonton: Alberta Education; 2007.
2. Assessment and Qualifications Alliance. GCE AS and A level subject criteria for science. London: Assessment and Qualifications Alliance; 2006.
3. Assessment and Qualifications Alliance. GCE AS and A level specification—Biology. London: Assessment and Qualifications Alliance; 2009.
4. Bada JL, Lazcano A. The origin of life. In: Ruse M, Travis J, editors. Evolution—The first four billion years. New York: Harvard University Press; 2009.
5. Board of Studies New South Wales. Biology stage 6 syllabus. Sydney: Board of Studies New South Wales; 2009.