@article{Carboni_1993,
    doi = {10.1016/0022-4049(93)90035-r},
    url = {https://doi.org/10.1016%2F0022-4049%2893%2990035-r},
    year = {1993},
    month = {feb},
    publisher = {Elsevier {BV}},
    volume = {84},
    number = {2},
    pages = {145--158},
    author = {Aurelio Carboni and Stephen Lack and R.F.C. Walters},
    title = {Introduction to extensive and distributive categories},
    journal = {Journal of Pure and Applied Algebra}
}

@article{Carboni_1993, doi = {10.1016/0022-4049(93)90035-r}, url = {https://doi.org/10.1016%2F0022-4049%2893%2990035-r}, year = {1993}, month = {feb}, publisher = {Elsevier {BV}}, volume = {84}, number = {2}, pages = {145--158}, author = {Aurelio Carboni and Stephen Lack and R.F.C. Walters}, title = {Introduction to extensive and distributive categories}, journal = {Journal of Pure and Applied Algebra} }