@INPROCEEDINGS{Leijen:flexibletypes,
  author   = {Daan Leijen},
  title    = {Flexible types: robust type inference for first-class polymorphism},
  booktitle= {{36th ACM SIGACT-SIGPLAN Symposium on Principles of Programming Languages (POPL'09)}},
  year     = 2009,
  month    = Jan,
  location = {Savannah, Georgia},
  note     = {Extended version available as Microsoft Research technical report {MSR-TR-2008-55}, Mar 2008}
}