@article{Hal_s_2012,
    doi = {10.1080/00207179.2011.651748},
    url = {https://doi.org/10.1080%2F00207179.2011.651748},
    year = {2012},
    month = {mar},
    publisher = {Informa {UK} Limited},
    volume = {85},
    number = {3},
    pages = {320--331},
    author = {Miroslav Hal{\'{a}}s and Ülle Kotta},
    title = {A transfer function approach to the realisation problem of nonlinear systems},
    journal = {International Journal of Control}
}

@article{Hal_s_2012, doi = {10.1080/00207179.2011.651748}, url = {https://doi.org/10.1080%2F00207179.2011.651748}, year = {2012}, month = {mar}, publisher = {Informa {UK} Limited}, volume = {85}, number = {3}, pages = {320--331}, author = {Miroslav Hal{\'{a}}s and Ülle Kotta}, title = {A transfer function approach to the realisation problem of nonlinear systems}, journal = {International Journal of Control} }