@Article{dovland10jlap,
  author = {Johan Dovland and Einar Broch Johnsen
            and Olaf Owe and Martin Steffen},
  title = {Lazy Behavioral Subtyping},
  journal = {Journal of Logic and Algebraic Programming},
  volume = 79,
  number = 7,
  pages = {578--607},
  year = 2010
}