Paul Shafer. Coding true arithmetic in the Medvedev and Muchnik degrees. Journal of Symbolic Logic, 76(1):267-288, 2011. [doi]
@article{Shafer11-0, title = {Coding true arithmetic in the Medvedev and Muchnik degrees}, author = {Paul Shafer}, year = {2011}, url = {http://projecteuclid.org/euclid.jsl/1294171000}, researchr = {https://researchr.org/publication/Shafer11-0}, cites = {0}, citedby = {0}, journal = {Journal of Symbolic Logic}, volume = {76}, number = {1}, pages = {267-288}, }