(Inggris) Jeremy M Berg, John L Tymoczko, dan Lubert Stryer (2002). Biochemistry. Johns Hopkins University School of Medicine, Carleton College, Stanford University (edisi ke-5). W. H. Freeman. hlm. Section 23.3 The First Step in Amino Acid Degradation Is the Removal of Nitrogen. ISBN0-7167-3051-0. Diakses tanggal 2011-09-11.Pemeliharaan CS1: Banyak nama: authors list (link)
(Inggris) Jeremy M Berg, John L Tymoczko, dan Lubert Stryer (2002). Biochemistry. Johns Hopkins University School of Medicine, Carleton College, Stanford University (edisi ke-5). W. H. Freeman. hlm. Figure 23.15 The Alanine Cycle. ISBN0-7167-3051-0. Diakses tanggal 2011-09-11.Pemeliharaan CS1: Banyak nama: authors list (link)