@article{Zhu_2009,
    doi = {10.1016/j.disc.2008.03.024},
    url = {https://doi.org/10.1016%2Fj.disc.2008.03.024},
    year = {2009},
    month = {sep},
    publisher = {Elsevier {BV}},
    volume = {309},
    number = {18},
    pages = {5562--5568},
    author = {Xuding Zhu},
    title = {Colouring graphs with bounded generalized colouring number},
    journal = {Discrete Mathematics}
}

@article{Zhu_2009, doi = {10.1016/j.disc.2008.03.024}, url = {https://doi.org/10.1016%2Fj.disc.2008.03.024}, year = {2009}, month = {sep}, publisher = {Elsevier {BV}}, volume = {309}, number = {18}, pages = {5562--5568}, author = {Xuding Zhu}, title = {Colouring graphs with bounded generalized colouring number}, journal = {Discrete Mathematics} }