@Article{HerlihyW91,
  author = 	 {M.P. Herlihy and J.M. Wing},
  title = 	 {Specifying graceful degradation},
  journal = 	 {IEEE Transactions on Parallel and Distributed Systems},
  year = 	 1991,
  volume =	 2,
  number =	 1,
  pages =	 {93--104},
  month =	 jul
}