@article{Flum_2003,
    doi = {10.1016/s0890-5401(03)00161-5},
    url = {https://doi.org/10.1016%2Fs0890-5401%2803%2900161-5},
    year = {2003},
    month = {dec},
    publisher = {Elsevier {BV}},
    volume = {187},
    number = {2},
    pages = {291--319},
    author = {Jörg Flum and Martin Grohe},
    title = {Describing parameterized complexity classes},
    journal = {Information and Computation}
}

@article{Flum_2003, doi = {10.1016/s0890-5401(03)00161-5}, url = {https://doi.org/10.1016%2Fs0890-5401%2803%2900161-5}, year = {2003}, month = {dec}, publisher = {Elsevier {BV}}, volume = {187}, number = {2}, pages = {291--319}, author = {Jörg Flum and Martin Grohe}, title = {Describing parameterized complexity classes}, journal = {Information and Computation} }