@inproceedings{ITiCSE-2010-KoppelmanD,
	author        = "Herman Koppelman and Betsy van Dijk",
	booktitle     = "{Proceedings of the 15th Conference on Innovation and Technology in Computer Science Education}",
	doi           = "10.1145/1822090.1822140",
	isbn          = "978-1-60558-729-5",
	pages         = "174--178",
	publisher     = "{ACM}",
	title         = "{Teaching abstraction in introductory courses}",
	year          = 2010,
}