Sam Sanders. ERNA and Friedman s Reverse Mathematics. Journal of Symbolic Logic, 76(2):637-664, 2011. [doi]
@article{Sanders11, title = {ERNA and Friedman s Reverse Mathematics}, author = {Sam Sanders}, year = {2011}, url = {http://projecteuclid.org/euclid.jsl/1305810768}, researchr = {https://researchr.org/publication/Sanders11}, cites = {0}, citedby = {0}, journal = {Journal of Symbolic Logic}, volume = {76}, number = {2}, pages = {637-664}, }