@article{Trejo_Ortiz_1998,
    doi = {10.1016/s0378-4754(97)00086-4},
    url = {https://doi.org/10.1016%2Fs0378-4754%2897%2900086-4},
    year = {1998},
    month = {jan},
    publisher = {Elsevier {BV}},
    volume = {45},
    number = {1-2},
    pages = {59--71},
    author = {Alejandro A.R. Trejo Ortiz and Guillermo Fern{\'{a}}ndez Anaya},
    title = {Regular expression simplification},
    journal = {Mathematics and Computers in Simulation}
}

@article{Trejo_Ortiz_1998, doi = {10.1016/s0378-4754(97)00086-4}, url = {https://doi.org/10.1016%2Fs0378-4754%2897%2900086-4}, year = {1998}, month = {jan}, publisher = {Elsevier {BV}}, volume = {45}, number = {1-2}, pages = {59--71}, author = {Alejandro A.R. Trejo Ortiz and Guillermo Fern{\'{a}}ndez Anaya}, title = {Regular expression simplification}, journal = {Mathematics and Computers in Simulation} }