 @book{card-book,
  title = {Introduction to {C}ardinal {A}rithmetic},
  author = {M. Holz and K. Steffens and E. Weitz},
  publisher = "Birkh{\"{a}}user",
  year = 1999,
  }

  @article{taylor-ordinals,
  author    = {Paul Taylor},
  title     = {Intuitionistic Sets and Ordinals},
  journal   = {J. Symb. Log.},
  volume    = {61},
  number    = {3},
  year      = {1996},
  pages     = {705-744},
  bibsource = {DBLP, http://dblp.uni-trier.de}
}
