- Friedberg numbering in fragments of Peano arithmetic and α-recursion theory, the Journal of Symbolic Logic, vol. 78, no. 4, December 2013, pp. 1135-1163.
- Δ2 degrees without Σ1 induction, Israel Journal of Mathematics, Accepted.
- Nonstandard models in recursion theory and reverse mathematics, with C. T. Chong and Yue Yang, the Bulletin of Symbolic Logic, volume 20, issue 02, pp. 170-200.