G. . Bastien and M. . Rogalski, “Difference equations on $\mathbb{R}_*^+$, of the form $u_{n+2}=\frac{f(u_{n+1})}{u_n+\lambda}$, $\lambda>0$, with applications to perturbations of dynamical systems”, sjm, vol. 18, no. 1, pp. 63–82, Jan. 2024.