@mastersthesis{com2pen00,
  author = {Aleksi Penttinen},
  title = {Mathematical models for marking in congestion pricing},
  school = {Helsinki University of Technology},
  note = {Master's Thesis},
  year = {2001},
  url = {http://www.netlab.hut.fi/tutkimus/com2/publ/Aleksi_dippa.pdf},
}