@incollection{de_Bruijn_1970,
    doi = {10.1007/bfb0060623},
    url = {https://doi.org/10.1007%2Fbfb0060623},
    year = {1970},
    publisher = {Springer Berlin Heidelberg},
    pages = {29--61},
    author = {N. G. de Bruijn},
    title = {The mathematical language {AUTOMATH}, its usage, and some of its extensions},
    booktitle = {Symposium on Automatic Demonstration}
}

@incollection{de_Bruijn_1970, doi = {10.1007/bfb0060623}, url = {https://doi.org/10.1007%2Fbfb0060623}, year = {1970}, publisher = {Springer Berlin Heidelberg}, pages = {29--61}, author = {N. G. de Bruijn}, title = {The mathematical language {AUTOMATH}, its usage, and some of its extensions}, booktitle = {Symposium on Automatic Demonstration} }