@inproceedings{CHI-2007-CockburnKAZ,
	author        = "Andy Cockburn and Per Ola Kristensson and Jason Alexander and Shumin Zhai",
	booktitle     = "{Proceedings of the 25th ACM SIGCHI Conference on Human Factors in Computing Systems}",
	doi           = "10.1145/1240624.1240863",
	isbn          = "978-1-59593-593-9",
	pages         = "1571--1580",
	publisher     = "{ACM}",
	title         = "{Hard lessons: effort-inducing interfaces benefit spatial learning}",
	year          = 2007,
}