@article{Silva_2004,
    doi = {10.1051/ita:2004003},
    url = {https://doi.org/10.1051%2Fita%3A2004003},
    year = {2004},
    month = {jan},
    publisher = {{EDP} Sciences},
    volume = {38},
    number = {1},
    pages = {49--67},
    author = {Pedro V. Silva},
    title = {Free group languages: Rational versus recognizable},
    journal = {{RAIRO} - Theoretical Informatics and Applications}
}

@article{Silva_2004, doi = {10.1051/ita:2004003}, url = {https://doi.org/10.1051%2Fita%3A2004003}, year = {2004}, month = {jan}, publisher = {{EDP} Sciences}, volume = {38}, number = {1}, pages = {49--67}, author = {Pedro V. Silva}, title = {Free group languages: Rational versus recognizable}, journal = {{RAIRO} - Theoretical Informatics and Applications} }