@InProceedings{stone+:singletons,
  author = 	 {Christopher A. Stone and Robert Harper},
  title = 	 {Deciding Type Equivalence in a Language with Singleton Kinds},
  booktitle = 	 twentyseventh # popl,
  pages =	 {214--227},
  year =	 2000,
  address =	 {Boston},
  month =	 {January}
}

@Article{stone+:singletons-tocl,
  author = 	 {Christopher A. Stone and Robert Harper},
  title = 	 {Extensional Equivalence and Singleton Types},
  journal = 	 {{ACM} Transactions on Computational Logic},
  year = 	 {2006},
  volume = {7},                  
  number =	 {4},
  pages =	 {676--722},
  month =	 {October}
}