@InProceedings{PR:99,
  author =    "Holger Pfeifer and Harald Rue{\ss}",
  title  =    "{Polytypic Proof Construction}",
  editor =    "Y. Bertot and G. Dowek and A. Hirschowitz and 
               C. Paulin and L. Th{\'e}ry",
  series =    "Lecture Notes in Computer Science",
  number =    "1690",
  pages  =    "55--72",
  booktitle = "Proc. 12th Intl. Conf. on Theorem Proving in Higher Order
		  Logics", 
  year   =    1999,
  publisher = "Springer-Verlag",
  month  =    sep
}