@inproceedings{KohLICS:04,
  year = 2004,
  booktitle = {Proc. of the 19th Annual IEEE Symposium on Logic in Computer
               Science (LICS 2004)},
  editor = {Ganzinger, H.},
  title = {An arithmetical hierarchy of the law of excluded middle and related
           principles},
  pages = {192-201},
  publisher = {IEEE Computer Society Press},
  author = {Akama, Yohji and Berardi, Stefano and Hayashi, Susumu and
            Kohlenbach, Ulrich},
}