1. Garey, M.R., Johnson, D.S.: Computers and intractability: a guide to the theory of NP-completeness. W. H. Freeman, San Francisco (1979)
2. Bell, T., Marghitu, D., Bell, J.: Workshop: CS Unplugged — computational thinking without computers. In: Pirkul, H., Spong, M.W., Shah, R., Suh, S. (eds.) Proceedings of SDPS 2011. Society for Design and Process Science, Jeju Island (2011)
3. Rosamond, F.: On-line and off-line computer games and mathematical sciences popularization. In: Rosamond, F., Copes, L. (eds.) Educational Transformations: The Influences of Stephen I. Brown, pp. 407–426. Authorhouse, Bloomington (2006)
4. Fellows, M.: Computer SCIENCE in the elementary schools. In: Fisher, N., Keynes, H., Wagreich, P. (eds.) Proceedings of the Mathematicians and Education Reform Workshop of Issues in Mathematics Education. Conference Board of the Mathematical Sciences, Seattle, vol. 3, pp. 143–163 (1991)
5. Casey, N.: Megamath: Expanding and connecting the mathematics community. In: INET 1995, Internet Society’s 1995 International Networking Conference, Honolulu, Hawaii (1995)