@article{Tarjan_1975,
    doi = {10.1145/321879.321884},
    url = {https://doi.org/10.1145%2F321879.321884},
    year = {1975},
    month = {apr},
    publisher = {Association for Computing Machinery ({ACM})},
    volume = {22},
    number = {2},
    pages = {215--225},
    author = {Robert Endre Tarjan},
    title = {Efficiency of a Good But Not Linear Set Union Algorithm},
    journal = {Journal of the {ACM}}
}

@article{Tarjan_1975, doi = {10.1145/321879.321884}, url = {https://doi.org/10.1145%2F321879.321884}, year = {1975}, month = {apr}, publisher = {Association for Computing Machinery ({ACM})}, volume = {22}, number = {2}, pages = {215--225}, author = {Robert Endre Tarjan}, title = {Efficiency of a Good But Not Linear Set Union Algorithm}, journal = {Journal of the {ACM}} }