@article{Hall_1935,
    doi = {10.1112/jlms/s1-10.37.26},
    url = {https://doi.org/10.1112%2Fjlms%2Fs1-10.37.26},
    year = {1935},
    month = {jan},
    publisher = {Wiley},
    volume = {s1-10},
    number = {1},
    pages = {26--30},
    author = {P. Hall},
    title = {On Representatives of Subsets},
    journal = {Journal of the London Mathematical Society}
}

@article{Hall_1935, doi = {10.1112/jlms/s1-10.37.26}, url = {https://doi.org/10.1112%2Fjlms%2Fs1-10.37.26}, year = {1935}, month = {jan}, publisher = {Wiley}, volume = {s1-10}, number = {1}, pages = {26--30}, author = {P. Hall}, title = {On Representatives of Subsets}, journal = {Journal of the London Mathematical Society} }