Paper  bibtex   

@ARTICLE{Zie06b,
  author = {Ziegler, Martin},
  title = {Effectively open real functions},
  journal = JC,
  year = {2006},
  volume = {22},
  pages = {827--849},
  number = {6},
  keywords = {bib,cca},
  url = {http://dx.doi.org/10.1016/j.jco.2006.05.002}
}