J. Matos, Y. Mor, R. Noss, и M. Santos. Fourth Congress of the European Society for Research in Mathematics Education (CERME-4), Sant Feliu de Guíxols, Spain, (2005)
E. Forster. Harcourt, San Diego, (1927)"The king died and then the queen died" is a story. "The king died, and then the queen died of grief" is a plot, page 84.