H. Iben, J. O'Brien, and E. Demaine. Proceedings of the twenty-second annual symposium on Computational geometry, page 71--79. New York, NY, USA, ACM, (2006)
X. Wu, and J. Johnstone. Computational Science and Its Applications - ICCSA 2006, volume 3980 of Lecture Notes in Computer Science, Springer, Berlin / Heidelberg, (2006)