S. Wahba, Y. Feaster, and J. Hallstrom. Proceedings of the 16th annual joint conference on Innovation and technology in computer science education, page 73--77. New York, NY, USA, ACM, (2011)
M. Gardner, and W. Feng. Proceedings of the fifteenth annual conference on Innovation and technology in computer science education, page 229--233. New York, NY, USA, ACM, (2010)