@incollection{Kozen_1996,
    doi = {10.1007/3-540-61042-1_35},
    url = {https://doi.org/10.1007%2F3-540-61042-1_35},
    year = {1996},
    publisher = {Springer Berlin Heidelberg},
    pages = {14--33},
    author = {Dexter Kozen},
    title = {Kleene algebra with tests and commutativity conditions},
    booktitle = {Tools and Algorithms for the Construction and Analysis of Systems}
}

@incollection{Kozen_1996, doi = {10.1007/3-540-61042-1_35}, url = {https://doi.org/10.1007%2F3-540-61042-1_35}, year = {1996}, publisher = {Springer Berlin Heidelberg}, pages = {14--33}, author = {Dexter Kozen}, title = {Kleene algebra with tests and commutativity conditions}, booktitle = {Tools and Algorithms for the Construction and Analysis of Systems} }