@inproceedings{Keller_2010,
    doi = {10.1145/1863597.1863601},
    url = {https://doi.org/10.1145%2F1863597.1863601},
    year = {2010},
    month = {sep},
    publisher = {{ACM}},
    author = {Chantal Keller and Thorsten Altenkirch},
    title = {Hereditary substitutions for simple types, formalized},
    booktitle = {Proceedings of the third {ACM} {SIGPLAN} workshop on Mathematically structured functional programming}
}

@inproceedings{Keller_2010, doi = {10.1145/1863597.1863601}, url = {https://doi.org/10.1145%2F1863597.1863601}, year = {2010}, month = {sep}, publisher = {{ACM}}, author = {Chantal Keller and Thorsten Altenkirch}, title = {Hereditary substitutions for simple types, formalized}, booktitle = {Proceedings of the third {ACM} {SIGPLAN} workshop on Mathematically structured functional programming} }