@INPROCEEDINGS{Leijen:helium,
  author    = {Bastiaan Heeren and Daan Leijen and Arjan van IJzendoorn},
  title     = {Helium, for Learning {H}askell},
  booktitle = {{ACM SIGPLAN} Haskell Workshop ({HW'03})},
  year      = 2003,
  month     = sep,
  publisher = {ACM Press},
  address   = {New York},
  pages     = {62 -- 71},
  pubcat    = {workshop},
}