@Article{J9,
  key =		 {J09},
  author =	 {Malte H\"ubner and Serge Autexier and Christoph
                  Benzm{\"u}ller and Andreas Meier},
  title =	 {Interactive Theorem Proving with Tasks},
  journal =	 {Electronic Notes in Theoretical Computer Science},
  volume =	 {103},
  number =	 {C},
  month =	 {November},
  year =	 2004,
  pages =	 {161-181},
  note =         {doi:10.1016/j.entcs.2004.02.021},
}