1. Weakly computable real numbers;Ambos-Spies;J. Complexity,2000
2. R.G. Downey, Some computability-theoretic aspects of reals and randomness, in: The Notre Dame Lectures, Lecture Notes in Logistics, vol. 18, Assoc. Symbol. Logic, Urbana, IL, 2005, pp. 97–147.
3. Degrees of d.c.e. reals;Downey;Math. Logic Quarterly,2004
4. Y.L. Ershov, A certain hierarchy of sets. i, ii, iii. (Russian), Algebra Logika 7(1) (1968) 47–73; 7(4) (1968) 15–47; 9 (1970) 34–51.
5. R. Rettinger, X. Zheng, On the Turing degrees of the divergence bounded computable reals, in: CiE 2005, June 8–15, Amsterdam, The Netherlands, Lecture Notes in Computer Science, vol. 3526, Springer, Berlin, 2005, pp. 418–428.