@article{Barto_2021,
    doi = {10.1145/3457606},
    url = {https://doi.org/10.1145%2F3457606},
    year = {2021},
    month = {jul},
    publisher = {Association for Computing Machinery ({ACM})},
    volume = {68},
    number = {4},
    pages = {1--66},
    author = {Libor Barto and Jakub Bul{\'{\i}}n and Andrei Krokhin and Jakub Opr{\v{s}}al},
    title = {Algebraic Approach to Promise Constraint Satisfaction},
    journal = {Journal of the {ACM}}
}

@article{Barto_2021, doi = {10.1145/3457606}, url = {https://doi.org/10.1145%2F3457606}, year = {2021}, month = {jul}, publisher = {Association for Computing Machinery ({ACM})}, volume = {68}, number = {4}, pages = {1--66}, author = {Libor Barto and Jakub Bul{\'{\i}}n and Andrei Krokhin and Jakub Opr{\v{s}}al}, title = {Algebraic Approach to Promise Constraint Satisfaction}, journal = {Journal of the {ACM}} }