@incollection{H_lzl_2013,
    doi = {10.1007/978-3-642-39634-2_21},
    url = {https://doi.org/10.1007%2F978-3-642-39634-2_21},
    year = {2013},
    publisher = {Springer Berlin Heidelberg},
    pages = {279--294},
    author = {Johannes Hölzl and Fabian Immler and Brian Huffman},
    title = {Type Classes and Filters for Mathematical Analysis in Isabelle/{HOL}},
    booktitle = {Interactive Theorem Proving}
}

@incollection{H_lzl_2013, doi = {10.1007/978-3-642-39634-2_21}, url = {https://doi.org/10.1007%2F978-3-642-39634-2_21}, year = {2013}, publisher = {Springer Berlin Heidelberg}, pages = {279--294}, author = {Johannes Hölzl and Fabian Immler and Brian Huffman}, title = {Type Classes and Filters for Mathematical Analysis in Isabelle/{HOL}}, booktitle = {Interactive Theorem Proving} }