Mingzhong Cai. Degrees of Relative Provability. Notre Dame Journal of Formal Logic, 53(4):479-489, 2012. [doi]
@article{Cai12-1, title = {Degrees of Relative Provability}, author = {Mingzhong Cai}, year = {2012}, url = {http://projecteuclid.org/euclid.ndjfl/1352383227}, researchr = {https://researchr.org/publication/Cai12-1}, cites = {0}, citedby = {0}, journal = {Notre Dame Journal of Formal Logic}, volume = {53}, number = {4}, pages = {479-489}, }