1. Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables;Abramovitz,1964
2. Irrationalité de ζ(2) et ζ(3);Apéry;Astérisque,1979
3. Rational Approximation of Eulerʼs Constant and Recurrence Relations,2007
4. A.I. Aptekarev, D.N. Tulyakov, Four-term recurrence relations for γ-forms, in [3], pp. 37–43.
5. A note on the irrationality of ζ(2) and ζ(3);Beukers;Bull. London Math. Soc.,1979