@incollection{Hansen_1989,
    doi = {10.1007/3-540-51237-3_11},
    url = {https://doi.org/10.1007%2F3-540-51237-3_11},
    year = {1989},
    publisher = {Springer Berlin Heidelberg},
    pages = {119--133},
    author = {Torben Amtoft Hansen and Thomas Nikolajsen and Jesper Larsson Träff and Neil D. Jones},
    title = {Experiments with implementations of two theoretical constructions},
    booktitle = {Logic at Botik {\textquotesingle}89}
}

@incollection{Hansen_1989, doi = {10.1007/3-540-51237-3_11}, url = {https://doi.org/10.1007%2F3-540-51237-3_11}, year = {1989}, publisher = {Springer Berlin Heidelberg}, pages = {119--133}, author = {Torben Amtoft Hansen and Thomas Nikolajsen and Jesper Larsson Träff and Neil D. Jones}, title = {Experiments with implementations of two theoretical constructions}, booktitle = {Logic at Botik {\textquotesingle}89} }