1. Optimal continued fractions
2. A.D. Brjuno, Analytical form of differential equations, Trans. Moscow Math. Soc. 25 (1971) 131–288 and 26 (1972) 199–239.
3. A. Cassa, Dinamiche caotiche e misure invarianti, Tesi di Laurea, Facoltà di Scienze Matematiche Fisiche e Naturali, University of Florence, Italy, 1995.
4. Critical functions for complex analytic maps;Marmi;J. Phys. A: Math. Gen.,1990