↑Jeremy M. Berg, John L. Tymoczko & Lubert Stryer: Biochemistry, 7th Edition, s. 989–990. W. H. Freeman and Company, 2012. ISBN 978-0-7167-8724-2(englanniksi)
↑Thomas Scott,Eric Ian Mercer: Concise encyclopedia biochemistry and molecular biology, s. 156–157. Walter de Gruyter, 1997. ISBN 978-3110145359(englanniksi)