- I. I. Batyrshin, “Irreducible, Singular, and Contiguous Degrees”, Algebra Logic, 56, № 3, 2017, 181
- Roland Sh Omanadze, “Some structural properties of quasi-degrees”, Logic Journal of the IGPL, 26, № 1, 2018, 191
- Irakli Chitaia, Keng Meng Ng, Andrea Sorbi, Yue Yang, “Incomparability in local structures of s-degrees and Q-degrees”, Arch. Math. Logic, 59, № 7-8, 2020, 777
- I. I. Batyrshin, “Q-reducibility and m-reducibility on computably enumerable sets”, Sib Math J, 55, № 6, 2014, 995