@article{Stra_burger_2012,
    doi = {10.1016/j.apal.2012.07.004},
    url = {https://doi.org/10.1016%2Fj.apal.2012.07.004},
    year = {2012},
    month = {dec},
    publisher = {Elsevier {BV}},
    volume = {163},
    number = {12},
    pages = {1995--2007},
    author = {Lutz Stra{\ss}burger},
    title = {Extension without cut},
    journal = {Annals of Pure and Applied Logic}
}

@article{Stra_burger_2012, doi = {10.1016/j.apal.2012.07.004}, url = {https://doi.org/10.1016%2Fj.apal.2012.07.004}, year = {2012}, month = {dec}, publisher = {Elsevier {BV}}, volume = {163}, number = {12}, pages = {1995--2007}, author = {Lutz Stra{\ss}burger}, title = {Extension without cut}, journal = {Annals of Pure and Applied Logic} }