@inproceedings{ITiCSE-WGR-2004-Henderson,
	author        = "Peter B. Henderson",
	booktitle     = "{Working Group Reports of the Ninth Conference on Innovation and Technology in Computer Science Education}",
	doi           = "10.1145/1044550.1041646",
	pages         = "22--24",
	publisher     = "{ACM}",
	title         = "{Penny piles}",
	year          = 2004,
}