1. Macintosh Human Interface Guidelines;Apple Computer Inc,1992
2. The Nurnberg Funnel: Designing Minimalist Instruction for Practical Computer Skill;Carroll,1990
3. European UNFOLD Project. Available from: http://www.unfold-project.net.
4. The Anti-Mac interface;Gentner;Communications of the ACM,1996
5. Why are some problems hard? Evidence from the Tower of Hanoi;Kotovski;Cognitive Psychology,1985