W. Xi, E. Fox, W. Fan, B. Zhang, Z. Chen, J. Yan, and D. Zhuang. SIGIR '05: Proceedings of the 28th annual international ACM SIGIR conference on Research and development in information retrieval, page 130--137. New York, NY, USA, ACM, (2005)
K. Ehrig, C. Ermel, S. Hansgen, and G. Taentzer. International Conference on Automated Software Engineering, page 134--143. Long Beach, CA, ACM Press, (November 2005)