@Unpublished{R22,
  key    =       {R22},
  author = 	 {Christoph Benzm{\"u}ller and Corinna Hahn (editors)},
  title = 	 {{The CALCULEMUS Midterm Report}},
  note = 	 {Unpublished EU Report, Saarland University, Saarbr{\"u}cken, Germany},
  month =	 {March},
  year =	 2003
}