@article{Flarup_2006,
    doi = {10.1002/malq.200510021},
    url = {https://doi.org/10.1002%2Fmalq.200510021},
    year = {2006},
    month = {jan},
    publisher = {Wiley},
    volume = {52},
    number = {1},
    pages = {37--50},
    author = {Uffe Flarup and Klaus Meer},
    title = {Two logical hierarchies of optimization problems over the real numbers},
    journal = {{MLQ}}
}

@article{Flarup_2006, doi = {10.1002/malq.200510021}, url = {https://doi.org/10.1002%2Fmalq.200510021}, year = {2006}, month = {jan}, publisher = {Wiley}, volume = {52}, number = {1}, pages = {37--50}, author = {Uffe Flarup and Klaus Meer}, title = {Two logical hierarchies of optimization problems over the real numbers}, journal = {{MLQ}} }