Grove, E.A., Lapierre, E. and Tikjha, W. 2012. On the global behavior of 𝑥ᵤ₊₁ = |𝑥ᵤ|− 𝑦ᵤ − 1 and 𝑦ᵤ₊₁ = 𝑥ᵤ +|𝑦ᵤ|. CUBO, A Mathematical Journal. 14, 2 (Jun. 2012), 111–152. DOI:https://doi.org/10.4067/S0719-06462012000200007.