@article{Ol_k_2017,
    doi = {10.1112/blms.12097},
    url = {https://doi.org/10.1112%2Fblms.12097},
    year = {2017},
    month = {oct},
    publisher = {Wiley},
    volume = {49},
    number = {6},
    pages = {1028--1047},
    author = {Miroslav Ol{\v{s}}{\'{a}}k},
    title = {The weakest nontrivial idempotent equations},
    journal = {Bulletin of the London Mathematical Society}
}

@article{Ol_k_2017, doi = {10.1112/blms.12097}, url = {https://doi.org/10.1112%2Fblms.12097}, year = {2017}, month = {oct}, publisher = {Wiley}, volume = {49}, number = {6}, pages = {1028--1047}, author = {Miroslav Ol{\v{s}}{\'{a}}k}, title = {The weakest nontrivial idempotent equations}, journal = {Bulletin of the London Mathematical Society} }