@incollection{Kunc,
    doi = {10.1007/978-3-540-73208-2_3},
    url = {https://doi.org/10.1007%2F978-3-540-73208-2_3},
    publisher = {Springer Berlin Heidelberg},
    pages = {23--27},
    author = {Michal Kunc},
    title = {What Do We Know About Language Equations?},
    booktitle = {Developments in Language Theory}
}

@incollection{Kunc, doi = {10.1007/978-3-540-73208-2_3}, url = {https://doi.org/10.1007%2F978-3-540-73208-2_3}, publisher = {Springer Berlin Heidelberg}, pages = {23--27}, author = {Michal Kunc}, title = {What Do We Know About Language Equations?}, booktitle = {Developments in Language Theory} }