Michael Kelly https://serc.carleton.edu/NAGTWorkshops/games/workshop08/kelly.html
Provenance Mike Kelly
Reuse This item is offered under a Creative Commons Attribution-NonCommercial-ShareAlike license http://creativecommons.org/licenses/by-nc-sa/3.0/ You may reuse this item for non-commercial purposes as long as you provide attribution and offer any derivative works under a similar license.
