@article{Milo_2003,
    doi = {10.1016/s0022-0000(02)00030-2},
    url = {https://doi.org/10.1016%2Fs0022-0000%2802%2900030-2},
    year = {2003},
    month = {feb},
    publisher = {Elsevier {BV}},
    volume = {66},
    number = {1},
    pages = {66--97},
    author = {Tova Milo and Dan Suciu and Victor Vianu},
    title = {Typechecking for {XML} transformers},
    journal = {Journal of Computer and System Sciences}
}

@article{Milo_2003, doi = {10.1016/s0022-0000(02)00030-2}, url = {https://doi.org/10.1016%2Fs0022-0000%2802%2900030-2}, year = {2003}, month = {feb}, publisher = {Elsevier {BV}}, volume = {66}, number = {1}, pages = {66--97}, author = {Tova Milo and Dan Suciu and Victor Vianu}, title = {Typechecking for {XML} transformers}, journal = {Journal of Computer and System Sciences} }