@techreport{plt-tr2009-gl-board-game-v4.2.1,
  author = {PLT},
  title = {{GL} Board Game: 3-D Game Support},
  number = {PLT-TR2009-gl-board-game-v4.2.1},
  type = {Reference Manual},
  institution = {PLT Scheme Inc.},
  month = {July},
  year = {2009},
  url = {http://download.plt-scheme.org/doc/4.2.1/pdf/gl-board-game.pdf},
  note = {\url{http://plt-scheme.org/techreports/}}
}