BibTex:

@studythesis{pfattner00topsy,
  author = {Marco Pfattner},
  title = {Structures and Interfaces of the Teachable Operating System Topsy},
  type = {Study Thesis},
  address = {Operating System Group, University of Erlangen, Germany},
  month = jun # "~14",
  year = 2000,
  url = {http://www4.informatik.uni-erlangen.de/SA/pdf/SA-I4-2000-07-Pfattner.pdf}
}