@inproceedings{Heeren_2003,
    doi = {10.1145/871895.871902},
    url = {https://doi.org/10.1145%2F871895.871902},
    year = {2003},
    month = {aug},
    publisher = {{ACM}},
    author = {Bastiaan Heeren and Daan Leijen and Arjan van IJzendoorn},
    title = {Helium, for learning Haskell},
    booktitle = {Proceedings of the 2003 {ACM} {SIGPLAN} workshop on Haskell}
}

@inproceedings{Heeren_2003, doi = {10.1145/871895.871902}, url = {https://doi.org/10.1145%2F871895.871902}, year = {2003}, month = {aug}, publisher = {{ACM}}, author = {Bastiaan Heeren and Daan Leijen and Arjan van IJzendoorn}, title = {Helium, for learning Haskell}, booktitle = {Proceedings of the 2003 {ACM} {SIGPLAN} workshop on Haskell} }