↑Thomas Scott,Eric Ian Mercer: Concise encyclopedia biochemistry and molecular biology, s. 525. Walter de Gruyter, 1997. ISBN 978-3110145359(englanniksi)
↑Jeremy M. Berg, John L. Tymoczko & Lubert Stryer: Biochemistry, 6th Edition, s. 551. W. H. Freeman and Company, 2006. ISBN 978-0-7167-8724-2(englanniksi)