@article{Chen_2002,
    doi = {10.1145/506147.506148},
    url = {https://doi.org/10.1145%2F506147.506148},
    year = {2002},
    month = {mar},
    publisher = {Association for Computing Machinery ({ACM})},
    volume = {49},
    number = {2},
    pages = {127--138},
    author = {Zhi-Zhong Chen and Michelangelo Grigni and Christos H. Papadimitriou},
    title = {Map graphs},
    journal = {Journal of the {ACM}}
}

@article{Chen_2002, doi = {10.1145/506147.506148}, url = {https://doi.org/10.1145%2F506147.506148}, year = {2002}, month = {mar}, publisher = {Association for Computing Machinery ({ACM})}, volume = {49}, number = {2}, pages = {127--138}, author = {Zhi-Zhong Chen and Michelangelo Grigni and Christos H. Papadimitriou}, title = {Map graphs}, journal = {Journal of the {ACM}} }