@article{riedl2008dynamic,
  title={Dynamic experience management in virtual worlds for entertainment, education, and training},
  author={Riedl, Mark O. and Stern, Andrew and Dini, Don and Alderman, Jason},
  journal={International Transactions on Systems Science and Applications Special Issue on Agent Based Systems for Human Learning},
  volume={4},
  number={2},
  pages={23--42},
  year={2008}
}