@InProceedings{HH03a,
  author = 	 {Paul Houston and Ralf Hartmann},
  title = 	 {Goal--Oriented A Posteriori Error Estimation for Compressible Fluid Flows},
  booktitle = 	 {Numerical Mathematics and Advanced Applications},
  pages =	 {775--784},
  year =	 2003,
  editor =	 {F. Brezzi and A. Buffa and S. Corsaro and A. Murli},
  publisher =	 {Springer}
}