↑Robert Hill & Joseph Needham. The Chemistry of Life: Eight Lectures on the History of Biochemistry (London, England: Cambridge University Press, 1970), page 17
↑Richard B. Silverman. The Organic Chemistry of Enzyme-catalyzed Reactions 2nd ed. (London, England: Academic Press, 2002), page 1
↑Jochanan Stenesh. Biochemistry, vol. 2 (New York, New York: Plenum, 1998), page 83
↑Robert A. Meyers, ed. Molecular Biology and Biotechnology: A Comprehensive Desk Reference (New York, New York: Wiley-VCH, 1995), page 296.