We define Markoff words as certain factors appearing in bi-infinite words satisfying the Markoff condition. We prove that these words coincide with central words, yielding a new characterization of Christoffel words. © 2007 Elsevier B.V. All rights reserved.
Glen, A., Lauve, A., & Saliola, F. V. (2008). A note on the Markoff condition and central words. Information Processing Letters, 105(6), 241–244. https://doi.org/10.1016/j.ipl.2007.09.005