@book {13830,
	title = {ACM Computing Surveys},
	series = {Online support systems},
	year = {1996},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0007575476\&partnerID=MN8TOARS},
	author = {Selber, S.A. and Johnson-Eilola, J. and Mehlenbacher, B.}
}