Kit Fine. The permutation principle in quantificational logic. J. Philosophical Logic, 12(1):33-37, 1983. [doi]
@article{Fine83, title = {The permutation principle in quantificational logic}, author = {Kit Fine}, year = {1983}, doi = {10.1007/BF02329199}, url = {http://dx.doi.org/10.1007/BF02329199}, researchr = {https://researchr.org/publication/Fine83}, cites = {0}, citedby = {0}, journal = {J. Philosophical Logic}, volume = {12}, number = {1}, pages = {33-37}, }