@techreport{shapes-tr,
  author = {Greenman, Ben and Muehlboeck, Fabian and Tate, Ross},
  title = {Getting F-Bounded Polymorphism into Shape},
  institution = {Cornell University},
  year = {2014},
  month = mar,
  url = {http://www.cs.cornell.edu/~ross/publications/shapes/}
}